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sjs
13-07-2015, 16:42
Following a number of requests for service, repairs and upgrades to the original SJS Arcadia line level pre-amplifiers, the time has come to declare that SJS Electroacoustics is once more operational

The following services are currently offered:

- service, upgrades, repairs and general tlc to the original SJS Arcadia amplifiers,
- bespoke commissions for single ended valve phono, line, headphone and power amplifiers

Many thanks for looking
Simon

sjs
07-08-2015, 13:44
A couple of weeks ago an original SJS Arcadia Model 1 line stage preamp last seen in 1997 came in for a service and full set of upgrades.

It was an early model built with 5687 valves and was in original condition, apart from a thick layer of dust throughout. The volume pot had become rather noisy,but otherwise all was good.

https://dl.dropboxusercontent.com/u/30444544/SJS/KS_line_1.jpg

It went through a full strip down, clean up, and complete rebuild:


Change to 6111wa valves
Tantalum resistors
Hovland, MusiCap and ClarityCap bypass caps on all electrolytics
Pure silver solid core signal wire with ptfe insulation
Alps Blue volume pot in shunt mode
NOS 5Y3GTA rectifier


https://dl.dropboxusercontent.com/u/30444544/SJS/KS_line_2.jpg

Should be good for a few more years

sjs
16-03-2016, 10:29
WE ARE PLEASED TO ANNOUNCE WE WILL BE EXHIBITING
AT THE NORTH WEST AUDIO SHOW (http://audioshow.co.uk/) ON SUNDAY 26TH JUNE 2016

https://dl.dropboxusercontent.com/u/30444544/SJS/sjspoststamp.jpg

THE SHOW
Now in its third year, the Northwest Audio Show is set to become one of the highlights in the audiophile calendar. With great exhibitors, top brands and a superb venue, we believe that the North West Audio Show gives attendees the opportunity to hear the very best audio in surroundings that are second to none. Register and secure your free tickets today. (https://www.eventbrite.co.uk/e/north-west-audio-show-16-tickets-14590892753?aff=es2&rank=1)

IT’S FREE
Free entry, free parking, a day surrounded by the best in audio and all in the beautiful settings of Cranage Hall and Wychwood Hall, Cheshire. The event organisers will also be laying on a free shuttle bus between the venues.

sjs
07-06-2016, 08:00
The first prototype SJS Aoide headphone amplifier is assembled and undergoing final testing.

https://dl.dropboxusercontent.com/u/30444544/SJS/headphone_amp_7.jpg

It is effectively a mW level integrated SET amplifier using triode strapped E55L valves, with custom designed and made HiB Double C core output transformers. These have secondaries which enable switching for low impedance (30 to 100 ohms) or high impedance (120 to 600 ohms) headphones, and either balanced or unbalanced connection. The PSU is valve rectified with choke input filter and second stage LC filters per channel. There are 3 line level inputs, input selector and volume control.

It came about as a result of a commission from a long time Model 1 preamp owner who has switched over to using Audeze headphones. It was designed to be an integrated amp, but a "power amp" version could be made for use with an existing preamp.

It's a prototype at the moment, and I need to sort out the switching arrangement and possibly get different wooden frames, but otherwise it's up and running quite nicely.

Almost forgot, it can also be built as a line stage pre-amplifier by changing the output transformers. I have this version built in another box which greengoblin heard recently when he visited.

The design was developed to match the phono stages built a few years ago

https://dl.dropboxusercontent.com/u/30444544/SJS/MD-overcase1.jpg

Any AoS members in South Manchester who are big headphone users and interested in hearing the prototype, please contact me

sjs
05-08-2016, 16:08
Last year I was asked to revamp a stereo SE 300B amplifier

It is the classic 6SN7-6SN7-300B circuit which has seen many implementations over the years, and for good reason because when it is well executed it can provide great results.

Having seen that work I was ask if I could implement the same amplifier in one of the chassis used for the Model 3 phono amplifier (http://theartofsound.net/forum/showthread.php?39613-SJS-Arcadia-Model-3-Valve-MM-Phono-Amplifier&p=667637#post667637)

After designing the layout and panels, the work of bringing it all together began

https://dl.dropboxusercontent.com/u/30444544/SJS/300B-stereo-2.jpg

https://dl.dropboxusercontent.com/u/30444544/SJS/300B-stereo-3.jpg

after completing the work on the top panel

https://dl.dropboxusercontent.com/u/30444544/SJS/300B-stereo-6.jpg

the next step was to mount the top panel into the chassis and wire up the back panel

https://dl.dropboxusercontent.com/u/30444544/SJS/300B-stereo-9.jpg

Finishing touches, and it is up and running nicely

https://dl.dropboxusercontent.com/u/30444544/SJS/300B-stereo-8.jpg

https://dl.dropboxusercontent.com/u/30444544/SJS/300B-stereo-7.jpg

sjs
05-08-2016, 16:10
About 15 years ago I was presented with a DAC built for me by a good friend who used to work at Audio Note, I have been using as-is ever since however I realised that it isn't the most handsome of DACs, nor the safest :shock: so it was time for a make over

Here is the customary before shot

https://dl.dropboxusercontent.com/u/30444544/SJS/dac_0.jpg

I decided to change to a valve rectified, choke input psu for the HT, and then separate mains tx for the heater supply and DAC board. some components upgrades throughout and a bit of a rearrangement to fit into a new chassis

https://dl.dropboxusercontent.com/u/30444544/SJS/dac_1.jpg

https://dl.dropboxusercontent.com/u/30444544/SJS/dac_2.jpg

overall seems like a worthwhile effort, bass impact has improved significantly and the midrange is cleaner with better depth and finesse

struth
05-08-2016, 16:16
Some pretty impressive handiwork there... All look lovely... The dac bar the 2 boards and 1 tx is completely changed lol

sjs
10-10-2016, 14:52
This week I have been enjoying a very nice Border Patrol P20 power amplifier.

https://dl.dropboxusercontent.com/u/30444544/SJS/BP_P20_1.jpg

2 x 300B per channel for around 18W of push pull goodness. This is the "low gain" version with a 6S45PI input/driver valve per channel and interstage driver/phase splitter transformer.

It has two outboard power supplies, making it effectively a three-box-dual-mono-amplifier

https://dl.dropboxusercontent.com/u/30444544/SJS/BP_P20_2.jpg

6 valve rectifiers :wow: each channel has a separate valve rectifier feeding a choke-input power supply for the output stage, driver stage and negative bias supplies, nice!

The amp came in for a check over, service and a few component upgrades. It was fitted with new 6S45PI valves*channel matched to within 0.1 dB, tantalum film resistors in the audio circuit, carbon film resistors in the PSU, new HT caps for the output stage and driver stage, and Elna Silmic II bypass caps for the driver stage and bias supply and quite a bit of re-wiring with solid core silver.

https://dl.dropboxusercontent.com/u/30444544/SJS/BP_P20_4.jpg

Overall a really nice improvement in clarity, tone and soundstage depth, whilst retaining that strength and dynamics the Border Patrol philosophy delivers.

Really nice sounding amp.

sjs
02-11-2016, 20:35
In a slightly tangential move compared to the valve amplifiers I generally get to work on, I was approach by Phil, The Count, and asked if I could help with his Snell AII loudspeakers.

In the time before marriage I was lucky enough to have a pair of Snell AII speakers for about 10 years, during which I refinished the wood veneer, replaced the grill cloth and worked on the crossovers, mainly replacing the old electrolytic caps with newer Black Gate bipolar caps :D

Phil had a problem, one of the tweeters had died. He had hunted down the appropriate replacements and supplied a new pair along with the speakers. First step was the assess the current situation......

Main unit with grill removed:
https://dl.dropboxusercontent.com/u/30444544/SJS/SnellAII_1.jpg

Inside to uncover the crossover for the midrange and tweeter:
https://dl.dropboxusercontent.com/u/30444544/SJS/SnellAII_2.jpg
Note the Audioquest speaker cable which is noticeably green under the clear cover :(

Then inside the bass cabinet to uncover the crossover:
https://dl.dropboxusercontent.com/u/30444544/SJS/SnellAII_3.jpg

Unfortunately, the "chuffing" noise in the low bass was caused by the perished foam surround on the bass unit:
https://dl.dropboxusercontent.com/u/30444544/SJS/SnellAII_4.jpg

Not a great result overall, but for speakers originally built in 1983 they weren't doing too badly. The worst problems were the (1) dead tweeter, (2) perished foam surround on one bass unit, and (3) copper oxide cables :(

Having one fully working unit, a bunch of measurements were taken to give an understanding of the baseline situation before any work was begun.
Acoustic measurements were taken of all 5 working drive units, with and without crossovers.
The crossovers were all taken apart carefully, the circuit drawn out and every component individually measured using an LCR meter.
The crossovers were then modelled in LTSpice in order to understand how they worked, and what the slight differences between left and right did to the output of the filters.
Very interesting :eek::rolleyes: :mental:

First off, replace the dead tweeter, unfortunately this required a switch of face plate:
https://dl.dropboxusercontent.com/u/30444544/SJS/SnellAII_5.jpg

Then strip down the bass unit to remove the perished foam surround:
https://dl.dropboxusercontent.com/u/30444544/SJS/SnellAII_6.jpg

Which seemed to work out quite nicely:
https://dl.dropboxusercontent.com/u/30444544/SJS/SnellAII_7.jpg

The bass crossover was then upgraded: replace the old cable; replace the inductor with a low dcr unit; and film caps to replace the old electrolytics:
https://dl.dropboxusercontent.com/u/30444544/SJS/SnellAII_8.jpg
The reduced dcr should help re-align the bass to work more nicely with the valve power amps Phil favours, and the film caps help to really improve the clarity of the bass.

Then the big challenge, the midrange and tweeter crossovers:
https://dl.dropboxusercontent.com/u/30444544/SJS/SnellAII_9.jpg
The old electrolytic caps were replaced with a combination of new bipolar and film caps, the cement clad resistors replaced, and all the old cable replaced.

All went back together, and it was then a long and careful process of integrating the new tweeters into the midrange. The new units were far more sensitive than the old ones, so they needed to be padded down, and it took a lot of measure/listen/tweak/repeat :brickwall: before the right balance was struck.

Definitely one of the more challenging projects, but very interesting, and hopefully a nice pair of speakers ready for many more years making music.

Gazjam
02-11-2016, 22:47
Super work Simon, inspires confidence you know your onions!

What trannies are you using in your 300B amp in the first photo?
Also, what hookup wiring are you using...looks like silver with teflon sleeving?

sjs
20-01-2017, 13:08
Inspired in part by some L'Amp and Le Monstre builds, it appears I am about to break a 25 year embargo on sand based amplifiers :hmm:

https://dl.dropboxusercontent.com/u/30444544/SJS/VFET-1.jpg

when I say "about", one must interpret that in a very loose way :rolleyes:

Designed by Nelson Pass using original Sony VFETs which he has personally tested and matched. It should be good for about 15W per channel, and as I want to use a bit R-core mains tx and LCLC PSU design it will be monoblocks.

Should be interesting.....

Mike Adams
03-02-2017, 16:34
Is this likely to be in a similar vein to Guy's Le Monstre build?

Id be keen to hear it once finished Simon, it would be an interesting comparison with the Border Patrol...

sjs
03-02-2017, 20:45
Similar but different to Guy's Monstre. Similar in that it is approx 15w class A SS amp; different in that it uses different types of output devices and I am thinking of a choke input psu, like in the BPs. Another build of this amp has already been described as being a bit like a PP300B amp, so comparison to yours should be quite entertaining.
But don't hold your breath, it could be quite some time.......

sjs
06-02-2017, 12:32
Just finished this little project making up a nice little SUT using Hashimoto HM-7 transformers.

Dual primaries can be switched for high/low impedance carts, and the grnd connection on the primary can be isolated for floating the MC coils. The casework is lined with mu metal sheet for screening, and solid core silver hook up wire and WBT silver loaded solder helps to up the foo factor :D

https://dl.dropboxusercontent.com/u/30444544/SJS/M9_SUT_1.jpg

https://dl.dropboxusercontent.com/u/30444544/SJS/M9_SUT_5.jpg

https://dl.dropboxusercontent.com/u/30444544/SJS/M9_SUT_2.jpg

https://dl.dropboxusercontent.com/u/30444544/SJS/M9_SUT_3.jpg

https://dl.dropboxusercontent.com/u/30444544/SJS/M9_SUT_4.jpg

Sounds really nice with my Ortofon cart, probably prefer it to the T-3000 as it has more body and a bit more drama to the presentation.

julesd68
06-02-2017, 14:57
That SUT just oozes quality, looks really nicely finished ...

Barry
06-02-2017, 18:52
Neat work - well done! :)

anubisgrau
06-02-2017, 21:38
Sounds really nice with my Ortofon cart, probably prefer it to the T-3000 as it has more body and a bit more drama to the presentation.

aaaah, no waaaay:=)

sjs
06-02-2017, 21:57
aaaah, no waaaay:=)
Yes way [emoji1]

Certainly seemed that way this afternoon. T-3000 had more precision and finesse, but hm-7 had more tone, structure and drama to the presentation.
Both very nice, but different [emoji1]

anubisgrau
06-02-2017, 23:19
we had recently HM-X vs T-5000 vs T-3000 shoot out, guess which stayed at the bottom :eyebrows:

sjs
06-02-2017, 23:24
I have had a couple of sets of HM-7 but not the HM-X. They seem to have similar specs, but the 7 has better LF extension and the X better HF. This suggests the X has fewer turns on the windings and less primary inductance, which may be a problem with some carts but not those with v low internal impedance.
It would be good to here an X and 7 together at some point.

anubisgrau
06-02-2017, 23:31
I have had a couple of sets of HM-7 but not the HM-X. They seem to have similar specs, but the 7 has better LF extension and the X better HF. This suggests the X has fewer turns on the windings and less primary inductance, which may be a problem with some carts but not those with v low internal impedance.
It would be good to here an X and 7 together at some point.

in my system, it had the same crazy detail extraction like both ortofons but lacked fluidity and tone. basically i would not say it was inferior, just very different, drier, and may need a more careful matching. or ortofon SUTs played to their strengths with my SPU... i would certainly not match it with lyra or AT, rather with something lush - koetsu

sjs
28-02-2017, 19:21
This year marks the 20th anniversary since the first SJS Arcadia Model 1 preamplifiers were delivered, so it's nice to have one come back for servicing and upgrades

https://dl.dropboxusercontent.com/u/30444544/SJS/SJS_Model1_3.jpg

This unit now has tantalum resistors, new psu caps, silver wire and new valves.

https://dl.dropboxusercontent.com/u/30444544/SJS/SJS_Model1_4.jpg


What was really good to see was one of only two matching mm phono stages which were built as prototypes

https://dl.dropboxusercontent.com/u/30444544/SJS/SJS_Model1_Phono_2.jpg

This shows it after it's rebuild with tantalum film resistors and new psu capacitors.

https://dl.dropboxusercontent.com/u/30444544/SJS/SJS_Model1_Phono_1.jpg

and this is the power supply

https://dl.dropboxusercontent.com/u/30444544/SJS/SJS_Model1_Phono_3.jpg

not bad for a phono amp :)

Firebottle
28-02-2017, 20:09
Beautiful construction there Simon :)

sjs
01-03-2017, 10:50
Beautiful construction there Simon :)

Thanks Alan

sjs
11-03-2017, 17:28
This week I have mainly been listening to volume controls #rubberroomcrazy

https://dl.dropboxusercontent.com/u/30444544/SJS/volume_pots.jpg

Can you name all 10? :)

hifinutt
11-03-2017, 17:52
oh my gosh , never knew there were so many types !

sjs
05-04-2017, 15:53
To celebrate 20 years since the first sjs arcadia Model 1 preamplifiers were delivered, we are pleased to announce a special 20th anniversary 20% discount on confirmed orders for any new sjs arcadia valve amplifier

https://dl.dropboxusercontent.com/u/30444544/SJS/Arcadia%20-%2020th%20anniversary%2020%25%20offer.jpg

This offer includes all current designs: Model 3 riaa, Model 5 se 300B, Model 6 riaa, Model 7 line, Model 8 se 300B amp, Aoide headphone amp

sjs
20-06-2017, 09:41
We are delighted to announce that we will again be exhibiting at the 4th edition of the NWAS which will take place in Cranage Hall and will run over 2 days.

We will be showing the SJS Arcadia amplifiers, Model 3 riaa, Model 5 SE 300B and Model 7 preamplifier complete with Living Voice (http://www.livingvoice.co.uk/) loudspeakers and valves, with Kondo cables.

http://3.bp.blogspot.com/--yUl5wlnXII/WOUYwkptPgI/AAAAAAAAFbg/8pawmmDFJs802kwm2sDyr3lEmFrmKrPCwCK4B/s1600/NWaudioshow2017-cropped-OnlinebannerPIGTHIS.jpg

THE SHOW
NWAS is set to become one of the highlights in the audiophile calendar. With great exhibitors, top brands and a superb venue, we believe that the North West Audio Show gives attendees the opportunity to hear the very best audio in surroundings that are second to none.

IT'S FREE
Free entry, free parking, a day surrounded by the best in audio and all in the beautiful setting of Cranage Hall, Cheshire. Book your free entry ticket(s) and enjoy a great audio festival at Cranage Hall in 2017 with best HiFi, live music, Audio Talks and more. Register and secure your free tickets today. (https://www.eventbrite.co.uk/e/north-west-audio-show-2017-tickets-28996120176?aff=erelexpmlt)

sjs
18-09-2017, 09:12
Hashimoto have announced a price rise of 8 to 11% across their entire range of transformers from 1st November.

The Model 9 SUT can be supplied with Hashimoto HM-3, HM-X or HM-7 mc step-up transformers, and special deals are available during October to beat the price rise.

Dual primaries can be switched for high/low impedance carts, and the grnd connection on the primary can be isolated for floating the MC coils. The casework is lined with mu metal sheet for screening, and solid core silver hook up wire and WBT silver loaded solder helps to up the foo factor :)

https://dl.dropboxusercontent.com/s/43m09hzr5rxgrp2/M9_SUT_1.jpg

https://dl.dropboxusercontent.com/s/ihg0nomhk0jun9t/M9_SUT_5.jpg

https://dl.dropboxusercontent.com/s/llfpcunj0wj9gox/M9_SUT_2.jpg

https://dl.dropboxusercontent.com/s/o6mnmg94m3gxldt/M9_SUT_3.jpg

https://dl.dropboxusercontent.com/s/d6oglgm9hgqrvj7/M9_SUT_4.jpg

More details are available on my blog:
http://sjselectroacoustics.blogspot.co.uk/2017/02/model-9-sut.html

sjs
09-11-2017, 16:14
Newly completed and ready for delivery, three SJS Model 9 SUTs

Hashimoto HM-7 transformers
pure silver wire with ptfe insulation
Dual primaries can be switched for high/low impedance carts
Ground connection on the primary can be isolated for floating the MC coils
MuMetal lined aluminium casework
WBT NexGen sockets and WBT silver loaded solder


https://dl.dropboxusercontent.com/s/hcvwdk65ny0xg8o/M9%20SUTs_3.jpg

https://dl.dropboxusercontent.com/s/9w1ipn6qe97no3e/M9%20SUTs_4.jpg

sjs
14-11-2017, 16:55
getting my first listen to Audio Note Non-Magnetic Silver Tantalum resistors and Dueland Hybrid capacitors in one of the copper cased SJS Arcadia Model 2 preamps back in for some tlc

https://dl.dropboxusercontent.com/s/wusp81c6ri1xnpk/SJS_Model2_newcaps.jpg

too early to make any detailed appraisal, as there are number of other changes:


new first HT cap and shunt resistor
new silver tantalum film resistors
new Dueland silver/copper hybrid capacitors
new phono sockets
new valves


I find the Dueland caps take at least a couple of days before they really settle down into what they do, but early signs of the whole shebang are really rather nice :eek:

sjs
28-01-2018, 20:09
An original Voyd turntable from about 1986 back in for repair. the psu had dead and needed all the voltage regs, darlingtons and fets replacing before it was up and running properly, then I replaced all the electrolytic caps to help it last the next 30 years

https://dl.dropboxusercontent.com/s/gy6s5yd7epuzfct/Voyd-1b.jpg

next up is this second Voyd turntable, which is one of the later units with the smaller sized Split Phase PSU, however this has 2 motors which have seized up. A full strip down and thorough clean up should see then right

https://dl.dropboxusercontent.com/s/vfh0vvzv1zrwa6f/Voyd-2b.jpg

sjs
02-04-2018, 18:54
The original Model 1 and 2 preamps, and the newer Model 7 preamp were all designed to work with valve power amps with a 100 kOhm input impedance.

They can be used successfully down to 50 kOhm, but I wouldn't recommend them for amps with a 20 kOhm or 10 kOhm input, which is now typical among a lot of solid state power amps.

This recently led to a challenge being presented when I was asked to develop a line stage preamp which could be used with a 10 kOhm input solid state power amp. Having thought about this I came up with two prototype amps rusttled up from parts left over form other amps, including a pair of rejected top panels from the Oyide headphone amps (http://theartofsound.net/forum/showthread.php?56668-SJS-Oyide-Headphone-Amplifier).

The first one uses a triode strapped 8608 pentode, to give a low plate impedance high gm triode, using custom made double C-core output transformers with a centre tapped secondary to provide a balanced or single ended output.

https://dl.dropboxusercontent.com/s/itjw3uivywev9bi/Proto-line_2.jpg

The second amp uses a 6EW7 double triode. The two triodes are dissimilar, and this uses the 2nd triode which has a mu of about 8 and plate impedance of less than 800 ohms. It is used with a choke load on the anode and output coupling caps.

https://dl.dropboxusercontent.com/s/pvxv4qku6altiiw/Proto-line_1.jpg

In the interest of fairness, both use the same mains TX and psu choke, both use a 5Y3 rectifier, with choke input and Mundorf HV+ cap, followed by an LC filter to each channel.

They have many similar characteristics, but also interesting differences.

sjs
18-05-2018, 14:09
This year marked the debut of SJS Electroacoustics Arcadia amplifiers at the Munich High End (http://www.highendsociety.de/index.php/en/high-end.html) show, probably the largest high end audio trade fair in Europe.

http://2.bp.blogspot.com/--EFFfT0krGw/Wv2dbl0EVgI/AAAAAAAAGLI/dh6athpHzDQDN282ofv5ukiKBsnIr_R3gCK4BGAYYCw/s1600/munich20180058.JPG

Two SJS Arcadia Model 3 Enhanced MM phono stage amplifiers were present, one in the Living Voice (https://www.livingvoice.co.uk/) room and the other in the Engström (https://www.engstromsound.com/) room.

The Living Voice room featured the Vox Olympian and Vox Elysium loudspeakers, partnered with vintage Kondo M77 and Gakuoh amplifiers. the vinyl front end was the Grand Prix Audio Monaco 2.0 (https://www.grandprixaudio.com/products/monaco-turntable-v20) turntable, with a Kuzma 4-point (http://www.kuzma.si/4point.html) tonearm, and a Fuuga MC (http://www.sakurasystems.com/fuuga.html) cartridge connected via a Living Voice step-up transformer to the Model 3 in oak with natural aluminium panels.

http://1.bp.blogspot.com/-ltbf7ifKcvk/Wv2aC9LShJI/AAAAAAAAGKw/WnBOFiALHl8C43yajCI3rf5Js5NYFLUzgCK4BGAYYCw/s1600/LVroom.jpg

The Engström room featured the Vox Palladian & Palladiam Basso loudspeakers, partnered with Engström Monica and Lars pre and power amp combination, or the new Arne 300B integrated amplifier. The vinyl front end was a Kuzma Stabi M (http://www.kuzma.si/stabi-m.html) turntable, with Stogi S 12 VTA tonearm and Van den Hul MC (https://www.vandenhul.com/product-category/phono/) catridge with a Kondo SFz (http://www.audionote.co.jp/en/products/transformer/sfz.html) step-up-transformers to the Model 3 in walnut with black aluminium panels.

http://4.bp.blogspot.com/-e8FV9u35gu0/Wv2czQ47SII/AAAAAAAAGK8/vRsThWbnSWEKCF7ve2hfRfqgTKj1tkfxgCK4BGAYYCw/s1600/31279471_201815303880659_6906474752483786752_n.jpg

Both Model 3 phono stages used in Munich were a customised version of the Enhanced Model 3. They were voiced in collaboration with Kevin Scott of Living Voice ahead of the show and feature NOS Shinkoh tantalum film resistors and Duelund Audio CAST copper coupling capacitors.

SJS Arcadia Model 3 phono amplifiers are available for demonstration at Definitive Audio (https://www.definitiveaudio.co.uk/) in Nottingham, or here in Manchester.

chris@panteg
20-05-2018, 09:33
I would go to Munich just for these two systems alone.

User211
20-05-2018, 12:35
I would go to Munich just for these two systems alone.I did go, but not for these two systems. However, the analogue front end sounded fabulous in the Olympian room and on one particular record I was very impressed indeed.

sjs
30-10-2018, 12:42
A couple more Voyd power supplies that were in need of some tlc.

On the left a late version split phase PSU which had failed on one phase. As it is about 30 years old, all the electrolytic caps were replaced, along with the darlington outputs and the small FETs. A couple of the resistors have a tendency to overheat, so they have also been replaced with higher power types.

https://dl.dropboxusercontent.com/s/bh4fcxyjtoy00em/Voyd_psu_4.jpg

On the right is a very old PSU, about the oldest type I have seen to date. The design and layout are both very different from the later units, but unfortunately it had a history of failure so it was decided to rebuild it as close as possible to the final design, like the unit on the left.

This meant a new mains tx to reduce the rail voltages, replacement of all the old electrolytic caps, the addition of voltage regulators for the oscillator and preamp stages, and a complete rebuild of the power stage.

The confined space and design of the original layout made it an interesting challenge, but all seems to have worked out nicely. :D

bumpy
30-10-2018, 16:23
Not a great result overall, but for speakers originally built in 1983 they weren't doing too badly.

I have drivers that are still performing brilliantly and are twice as old as those. Makes me wonder how far Hi-Fi has come in all those years :)

sjs
12-03-2019, 10:19
It is two years since the first of the new SJS Arcadia Model 7 (http://sjselectroacoustics.blogspot.com/2017/03/sjs-arcadia-model-7-line-pre-amplifier.html) linestage preamplifiers were developed.

During this time we have continued with research and development to further refine the musicality of the amplifiers, as well as offering both a Standard and Enhanced version of the design.

The Standard version has carbon film resistors and an RC couple gain stage:

https://dl.dropboxusercontent.com/s/ewp4vhpuy9wrfsx/SJS_Model7_Std_line_6.jpg

https://dl.dropboxusercontent.com/s/ewp4vhpuy9wrfsx/SJS_Model7_Std_line_7.jpg


The Enhanced version has tantalum film resistors, a choke loaded LC couple gain stage and enhanced psu choke:

https://dl.dropboxusercontent.com/s/2kchs8damevi1kn/SJS_Model7_Enh_line_8.jpg

https://dl.dropboxusercontent.com/s/bhhnbh8igzvhawy/SJS_Model7_Enh_line_5.jpg

Both versions feature 6111wa NOS military twin triode valves in the gain stage, Duelund Coherent Audio copper foil coupling capacitors, and the common SJS design elements:


Single Ended circuit topology
Pure Class A operation
Zero negative feedback
Valve rectification and choke-input HT power supply
Custom made HT T-network power supply capacitors with silver leads
Point-to-point circuit wiring without PCBs
Hand built
PTFE board for component mounting
High quality components throughout
Custom made aluminium chassis


Each amplifier comes with 2 years parts a labour warranty, except for the valves which have a 6 month warranty.

SJS Arcadia amplifiers are available from Definitive Audio (https://www.definitiveaudio.co.uk/news.html) in Nottingham.

Avinunca1
12-03-2019, 12:39
SJS Arcadia amplifiers are available from Definitive Audio (https://www.definitiveaudio.co.uk/news.html) in Nottingham.[/QUOTE]

I could not see any reference to SJS on the website linked to

sjs
12-03-2019, 15:01
duplicate post removed

sjs
12-03-2019, 15:05
"SJS Arcadia amplifiers are available from Definitive Audio (https://www.definitiveaudio.co.uk/news.html) in Nottingham."

I could not see any reference to SJS on the website linked to

Micheal

If you scroll down the linked News page there is an entry from February 2017:

"Out of the box thinking… in beautiful boxes.
Highly individual circuit designs which bring life, expression and vitality to the musical performance that delights and bedazzles in equal measure. Knockout. Definitive Audio is excited to be representing the full range of SJS Electroacoustics."

Definitive Audio currently have the following available for audition: Model 3 phono, Model 5 SE 300B power amp and Model 7 preamplifier.

Conversely, if Manchester is more convenient you can audition them here.

More info is also available on our blog: http://sjselectroacoustics.blogspot.com/

All the best
Simon

sjs
10-04-2019, 13:19
Five armboards for Voyd turntables waiting to be dispatched

https://dl.dropboxusercontent.com/s/ucs5rhdsbpr5cao/Voyd-armboards.jpg

Four standard armboards in 3mm anodised aluminium for Fidelity Research FR-64fx or s, Kuzma Stogi Reference, Helius Omega and SME

plus a 10mm "reference" armboard for FR-64fx or s in black powdercoat finish

chris@panteg
15-04-2019, 17:35
How much are the armboards?

sjs
16-05-2019, 14:12
Just collected this original SJS Arcadia 18w power amplifier. It is in for a service and thorough check over before it goes up for sale

PSE 300B with dual-mono external psu

https://dl.dropboxusercontent.com/s/iuvqsuz8avqfdgr/Arcadia18w_1.jpg

crimsondonkey
16-05-2019, 14:47
Bloody hell that's nice :eek:

chris@panteg
16-05-2019, 16:17
Stunning amplifier.

AJSki2fly
16-05-2019, 16:20
Just collected this original SJS Arcadia 18w power amplifier. It is in for a service and thorough check over before it goes up for sale

PSE 300B with dual-mono external psu

https://dl.dropboxusercontent.com/s/iuvqsuz8avqfdgr/Arcadia18w_1.jpg

Would that happen to be owned by a chap by the name of David W.? If it is then may be the one he brought to my house to listen to some gear, and it certainly sounded very impressive.

sjs
16-05-2019, 17:21
Would that happen to be owned by a chap by the name of David W.? If it is then may be the one he brought to my house to listen to some gear, and it certainly sounded very impressive.Similar, but different :-)
He has a PSE 2A3 version, without external psu, but with some recent internal upgrades.
I hope you didn't have to lift it !!!

sjs
30-05-2019, 19:10
Four more armboards waiting to be shipped out

https://dl.dropboxusercontent.com/s/pfl28ezswn1k9pe/Voyd-armboards_2.jpg

Two standard arm boards in 3mm anodised aluminium for Fidelity Research FR-64fx or s at 230mm and one for Kuzma Stogi Reference

The top two are black powder coated aluminium, on the left is a Rega / AN Arm-1 arm board for a Voyd Valdi, and on the right is a 10mm reference board for a Rega / AN Arm-1 on a Voyd

dwhistance
30-05-2019, 19:28
My amplifier certainly isn't for sale but will be heading back to Simon at some stage for an external power supply, my only problem is finding a place for the extra box!

David Whistance

sjs
18-06-2019, 16:50
An early Voyd split phase psu in for repairs and servicing. The light in the power switch didn't work, and on one of the speed settings the motors weren't running.

Inside there was evidence of a previous repair, and after some effort the faults were identified and the psu returned to operation.

https://dl.dropboxusercontent.com/s/sggtgqmnian0d73/Voyd_psu_5.jpg

https://dl.dropboxusercontent.com/s/db82rcwqjkxrk1x/Voyd_psu_6.jpg

New electrolytic caps, regulators, transistors and darlington output pairs, plus a few resistors. New mains switch, small heatsinks on the regulators and transistors which tend to get a bit warm, and finally a good clean

Should be good to go for some time yet

chris@panteg
19-06-2019, 10:35
Many thanks Simon, excellent work with great patience and perseverance I suspect.
It's performing superbly.

sjs
10-01-2020, 16:37
An original Arcadia 18W PSE 300B amplifier has been in for servicing and repairs.

Originally supplied in 1997 it was enhanced with a large external dual-mono power supply in 2004.

https://dl.dropboxusercontent.com/s/axns391yauxiqi5/BJ-outside1.jpg

Following a number of amendments, and a period of time in storage, it has been thoroughly repaired and serviced. A couple of damaged chokes have been replace, some of the psu capacitors replaced, a new pair of 6072A input and 5687WB driver valves, and a new set of EH Gold Grid 300Bs are now being used instead of the TJ mesh plate 300B/n valves shown.

https://dl.dropboxusercontent.com/s/t4xg235u0v023m3/BJ-psu1.jpg

The PSU contains a large mains transformer for each channel, plus valve rectifiers, choke input and first psu cap for the input/driver psu. The psu is remotely switched on/off from the main chassis.

https://dl.dropboxusercontent.com/s/6u0leg5ho5izjbe/BJ-inside1.jpg

Inside the main chassis there are two mains transformers for the 300B filament supplies, and six more chokes for the various power supplies.

In total there are three valve rectified, choke input filtered power supplies per channel, making six in total. One for the 300Bs, the second for the input/driver stage, and the third for the negative bias supply.

https://dl.dropboxusercontent.com/s/bqap37hjnqakpg7/BJ-inside2.jpg

The components inside are typical of the period, including Elna Cerafine HT caps for the 300B ht, a lot of Black Gates, Hovland coupling caps, Mills and Rhopoint wirewound and even a couple of tantalum film resistors.

The servicing should see it good for many years to come.

sjs
25-01-2020, 22:10
https://dl.dropboxusercontent.com/s/7zyabyfhrfigvsd/Bristol2020.jpg

We are pleased to announce that we will be exhibiting at the The Bristol Hi-Fi Show 2020

See SJS Arcadia amplifiers with Living Voice in Room 413 on the 4th Floor and in Room 415 on the 4th Floor

We look forward to seeing you there!


Location

Marriott City Centre Hotel, Lower Castle Street, Bristol, BS1 3AD

First Floor, Room 118

Opening Hours

Opening Hours
Friday 21st to Sunday 23rd February 2020
10am – 5pm

For more information and tickets for the show, visit The Bristol Hi-Fi Show website, here (https://www.bristolshow.co.uk/).

sjs
06-02-2020, 10:39
Further details of the Bristol Show with Living Voice and Kuzma can be seen on the Definitive Audio website.


https://www.definitiveaudio.co.uk/

Sent from my SM-G960F using Tapatalk

sjs
12-10-2020, 12:51
A thoroughly enjoyable day last weekend with Kevin and Lynn at Definitive Audio,
delivering a few SJS Arcadia Model 7 line preamplifiers looking stealthy in the new all black finish,
and enjoying the new Living Voice R4 Avatar IBX-RW loudspeakers and vinyl spinning on the Kuzma Stabi R turntable in orange, and the Grand Prix Audio Monaco

https://dl.dropboxusercontent.com/s/gedsi23g07flxbd/SJS_Model7_line_14.jpg