Anyone remember JDI pre / monoblocks?

[nat8808]

Anyone remember JDI pre amps and monoblocks?

They're from around '89 and an English brand, amybe from Cambridge and distributed by Castle Acoustics. Quite expensive gear too.

Have opportunity to buy the pre and finding it hard to find any info other than a quoted Gramaphone magazine reference (Gramaphone Archive has been taken behind a paywall now... :( )

[Mr Kipling]

One was on eBay last week or the week before. It was quite a high feedback design with fast power supplies which were housed in a separate encloseure. Both pre and power supply were bolted to an integral stand. Alvin Gold, I think, reviewed it for The Audiophile and quite liked it. I have it somewhere, if I can find it.

[SCIDB]

Hi,

I remember these from the late 80s. To my ears, they were a very fine sounding combo. It had good resolution and detail. I remember being very impressed at the time.

Here is a quote from a query I have seen on Hifi Wigwam from a few years ago.

JDI amp review from Gramophone (1989)..

"The Skipton company Castle Acoustics have for some time been liaising with a new British amplifier manufacturer, JDI Amplification, also based in Yorkshire at nearby Ilkley. Castle are now handling all UK and overseas marketing for JDI and at Penta were showing for the first time a two-box preamplifier (signal circuitry in one, power supply in the other) and a monoblock power amplifier. Wide bandwidth, high speed (i.e. transient response) and low noise were the design prerequisites and to this end a novel power supply is used for the preamplifier which has a kind of balanced mode operation which apparently does away with the usual reservoir capacitors and maintains a constant source impedance throughout the audio band. A high accuracy moving-coil only phono stage is fitted which has a claimed dynamic range of 107dB. The power amplifier uses Class A circuits up to the output stage, which then reverts to high accuracy Class AB operation. I was by no means alone in admiring the extremely elegant presentation and cabinet design of these new units. The combination of preamplifier and two mono power amplifiers retails for £3,300."

Rated output power is 60w RMS into 8 ohm

[Rare Bird]

Yup i remember them with their shiney facias, looked really nice, my local Hi-Fi dealer at the time had some JDI stuck on a rack for quite some time, this would be the time Castle Acoustics Ltd dealt with Jeklin Float headphones too.. ( i remeber them clearly as it was the same time i bought an old Townshend 600 Pre/Monoblocks from him 2nd hand)..

[nat8808]

Yup i remember them with their shiney facias, looked really nice, my local Hi-Fi dealer at the time had some JDI stuck on a rack for quite some time, this would be the time Castle Acoustics Ltd dealt with Jeklin Float headphones too.. ( i remeber them clearly as it was the same time i bought an old Townshend 600 Pre/Monoblocks from him 2nd hand)..

Oo, fine taste Sir - always fancied trying the Townshend 600 system but feel I've missed my chance as they used to sell for £200 on ebay, an unknown set. Now too many people on there pushing up prices so would expect nearer £500.

What were they like?

[nat8808]

One was on eBay last week or the week before. It was quite a high feedback design with fast power supplies which were housed in a separate encloseure. Both pre and power supply were bolted to an integral stand. Alvin Gold, I think, reviewed it for The Audiophile and quite liked it. I have it somewhere, if I can find it.

That's the one - hoping to sort something out off eby as it didn't sell.

If you could find the Audiophile review I would be very greatful. i've some Audiophiles around so will have a look too. Old magazines are very handy, although always the brief reviews of non-mainstream stuff that are more interesting but you never know what reviews are in them when picking them up secondhand.

I'm on a bit of a pre-amp trip at the moment, so looking out for rare 80s 90s gear (the era I seem to like - kind of a time for cottage industry high end without all the bling of the '00s)

Surprised and pleased to get so many responses

[nat8808]

Hi,

I remember these from the late 80s. To my ears, they were a very fine sounding combo. It had good resolution and detail. I remember being very impressed at the time.

Here is a quote from a query I have seen on Hifi Wigwam from a few years ago.

JDI amp review from Gramophone (1989)..

"The Skipton company Castle Acoustics have for some time been liaising with a new British amplifier manufacturer, JDI Amplification, also based in Yorkshire at nearby Ilkley. Castle are now handling all UK and overseas marketing for JDI and at Penta were showing for the first time a two-box preamplifier (signal circuitry in one, power supply in the other) and a monoblock power amplifier. Wide bandwidth, high speed (i.e. transient response) and low noise were the design prerequisites and to this end a novel power supply is used for the preamplifier which has a kind of balanced mode operation which apparently does away with the usual reservoir capacitors and maintains a constant source impedance throughout the audio band. A high accuracy moving-coil only phono stage is fitted which has a claimed dynamic range of 107dB. The power amplifier uses Class A circuits up to the output stage, which then reverts to high accuracy Class AB operation. I was by no means alone in admiring the extremely elegant presentation and cabinet design of these new units. The combination of preamplifier and two mono power amplifiers retails for £3,300."

Rated output power is 60w RMS into 8 ohm

The guy selling it (the pre) said it replaced and bettered his PT PiP2 which is high praise indeed. In research, I noticed an Audio Note 3 pre for sale with JDI amps so perhaps a way of getting detail and resolution with AudioNote lushness.

Phono stage with a claimed 107dB dynamic range.. certainly that reads impressively.

[Mr Kipling]

The review was in the Aug '90 of The Audiophile and was indeed by Alvin Gold. Thought it was two pages but it's just one. It was £2,500 at the time.

If you want to give an address I'll get it copied on Monday.

[nat8808]

ooo, thanks Stephen! I tell you what, I'll have a search through my Audiophiles and see if I have it and then PM with my address if not.

I think I've some from around 92/93 or so though, not 90.

Interesting magazine Audiophile in that it often has some rarity reviewed that you can't find info on anywhere else. Might have to collect a few more from ebay or whereever.

[Mr Kipling]

I did intend to say more but I lost my first reply and was too aggravated as it's been happening a number of times today.

It has 3 main blocks which are the m.c., R.I.A.A, and line level. The signal circuitry is said to be quite simple with the power supply being complex for providing a suitable environment for the signal side, and this is where the high levels of feedback are employed. A star-earth wasn't used as the designer thought it resulted in unequal path lengths and complexity. There's also no reservoir capacitor on the transformer. A result of the complex power supplies is that it's immune from mains effects. The case was acrylic and frame aluminium.

[Rare Bird]

Oo, fine taste Sir - always fancied trying the Townshend 600 system but feel I've missed my chance as they used to sell for £200 on ebay, an unknown set. Now too many people on there pushing up prices so would expect nearer £500.

What were they like?

Very good, putting aside the Pre's outboard plastic box power supply, it was a super pre-amp, very thick extruded aluminium sleeve. Loved the way the rear was contructed at an angle so all the socketry fired upwards. Never ever seen the power amps for sale since..

The Townshend Pre/Pwr..Rock/Merlin/Excalibur/555 was one hell of a good system.

[Rare Bird]

The review was in the Aug '90


'89/'90 sounds about right because they were there when i bought my Radford 'WSCD1' CD Player around that time..

[Mr Kipling]

And here's the front cover, André.

[Rare Bird]

I also bought a Rose 'RV23' around that time maybe a year or so later, that was a nice toobe Pre amp, very well built & nicely laid out inside.

[Mr Kipling]

Both that and the Townsend preamp were review in 'Answers/Audiophile and got positive reviews.

[Rare Bird]

Aye the matching Rose power amp was a transistor amp tho.

[nat8808]

Very good, putting aside the Pre's outboard plastic box power supply, it was a super pre-amp, very thick extruded aluminium sleeve. Loved the way the rear was contructed at an angle so all the socketry fired upwards. Never ever seen the power amps for sale since..

The Townshend Pre/Pwr..Rock/Merlin/Excalibur/555 was one hell of a good system.

I've seen a few sets on ebay over the years but probably about once every 3 years.. Like all rare occurances, there's a kind of exponential fall off in chance of you and it crossing paths unless you're constantly going through everything listed. Add in short lasting BINs and the chance is even less..

I've a naked MC555 - was nice until the suspension came upstuck.. Must get it repaired if I can. Love the green case.

And I've a Radford WSCD3 too...though again needing a repair. This all comes from me reading old Hifi News's and spotting things secondhand. Sounds like you were enjoying he gear I was enthusing over but some 20 years beforehand..

[nat8808]

The review was in the Aug '90 of The Audiophile and was indeed by Alvin Gold. Thought it was two pages but it's just one. It was £2,500 at the time.

If you want to give an address I'll get it copied on Monday.

I've just realised that you mean photocopied and posted? I don't have the mag myself so I would be very greatful for a copy.

However, what do you reckon to just taking a photo of the page? Would your camera focus well enough on the page so the text was clear (with no flash glare)? Then a high enough res photo would be fine (or two photos, half a page each).

Wouldn't want you to spend on postage unnessecarily.

[Mr Kipling]

I've tried. I only have my mobile and to get the text in focus takes a total of 10 shots. I can stretch to a stamp, an envelope and photo copy charge.

[The Grand Wazoo]

I've got a copy but my scanner's out of action. Give me a few minutes & I'll sort something for you.

[The Grand Wazoo]

Try this.
Let me know when you're done because the images are massive files and I'd like to clear them off.

http://imageshack.us/a/img854/2860/dscf5527.jpg

http://imageshack.us/a/img820/5136/dscf5528s.jpg

There's also a little piece I didn't photograph in the Right to Reply section at the end of the magazine where Castle Acoustics basically say thanks for a nice review.

[Rare Bird]

Aye wi kno's arter meck propur Hi-Fi oop ere loike laddie.

[nat8808]

Thanks so much for that Chris ! And saved Stephen some copying and posting.

Thanks to both of you for the help.. It sounds pretty good - I like the DNM high resolution kind of sound, with the lushness and warmth that is inherently in the recording allowed to come out with all harmonics and microtones intact and not artificial warmth imparted by a kind of smoothing out by the gear.

So I'll have to see how I get on with the price and getting funds together if ok.

[nat8808]

Aye wi kno's arter meck propur Hi-Fi oop ere loike laddie.

Fred Dibnah from the grave..

[Macca]

Fred Dibnah from the grave..

lol

[Rare Bird]

Fred was from Lancashire not Yorkshire ;)

[hifi_dave]

Pedant..;)

[Rare Bird]

Pedant! Yorkshire isnt Lancashire It's as simple as that, we don't even speak the same.

[Macca]

Yorkshire isnt Lancashire It's as simple as that,

Very true - Lancashire is in a better class entirely ;)

[Mr Kipling]

Not heard of the Wars of the Roses Pop Pickers?

[nat8808]

Fred was from Lancashire not Yorkshire ;)

Yes ! It was a deliberate attempt to create conflict.... ahem, honest!

Still, he had an amazing accent.

[Rare Bird]

http://www.ebay.co.uk/itm/JDI-PSU-power-supply-for-Roksan-Xerxes-Incredibly-rare-high-end-equipment-/200909356397?pt=UK_AudioTVElectronics_HomeAudioHiF i_Turntables&hash=item2ec7217d6d

[Nuisance Value]

Hi there, the reason I joined this forum was to share this info on some JDI.

About fifteen years ago I was lucky enough to find my current speakers were up for sale from the guy that built them, so I bought them due to the fact they were unique and were exactly what I was looking for in terms of bass response.

The only problem this posed was powering them! After I had paid for the speakers he also offered me the chance to buy some amps to power them. He had kind of deigned the speakers to work in tandem with these JDI pre & mono blocks so it was an obvious choice.

How he came to have them I'm not sure but he was once in the R&D department for Wharfedale so I guess he knew a few people in the business so to speak.

Anyway, I bought the pre amp and six mono blocks which meant that I could run the speakers active (he also gave me some crossovers for running them passive should I wish) and the active crossover components so I could build that too.

He also had some literature and gave me a framed picture of the JDI advertising (the pic below) but this is all I have. I've scanned it, because as you say, there is virtually no info on these amps on the internet.

http://i733.photobucket.com/albums/ww333/Nuisance-Value/JDIamp001.jpg (http://s733.photobucket.com/user/Nuisance-Value/media/JDIamp001.jpg.html)

http://i733.photobucket.com/albums/ww333/Nuisance-Value/JDIamp002.jpg (http://s733.photobucket.com/user/Nuisance-Value/media/JDIamp002.jpg.html)

[Alex_UK]

That's good of you Nick, thanks for sharing.

[Nuisance Value]

That's good of you Nick, thanks for sharing.

You're welcome. As it happens, this pre-amp is on eBay at the moment.. Good price considering new they were £3.5k

http://www.ebay.co.uk/itm/140975549402?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

[Nuisance Value]

Gents, apologies to resurrect this topic, but in light of below, I'm trying to ascertain if I should be using a low output or high output MC cartridge?

High Output Sumiko BPS - 2.5mV

Low Output Sumiko BPS - 0.5mV

I've been using a high output Sumiko BPS, but they do a low output one as well. With the high output, volume is pretty loud at half volume, would a low output be approx one fifth of this, and is there any discernible advantage to one or the other?

Thanks


Hi,

I remember these from the late 80s. To my ears, they were a very fine sounding combo. It had good resolution and detail. I remember being very impressed at the time.

Here is a quote from a query I have seen on Hifi Wigwam from a few years ago.

JDI amp review from Gramophone (1989)..

"A high accuracy moving-coil only phono stage is fitted which has a claimed dynamic range of 107dB."

Rated output power is 60w RMS into 8 ohm

[Light Dependant Resistor]

Hi Nick
It is easier to attenuate vs amplify. Given the high output version exists - getting that initial output
higher at the cartridge source would IMO be better, than say exploring losses and greater amplification
error later

Cheers / Chris

[Nuisance Value]

Hi Chris,

Thanks for that, I was wondering the same. I think I'll stick with the high output.

[Nuisance Value]

Quick heads up, there's a pair of these for sale on ebay at the moment (not mine i should add)..

https://www.ebay.co.uk/itm/304080793208