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View Full Version : my everchanging sytem !!!



jcgrant
14-12-2009, 17:25
hi my names is james and here is my ever changing system!!

my homebuild valve amp (from a kit) based on a st70 push pull amp using KT66 ouput valves(better for bass I'm told) and some 12at7 driver tubes the one in the centre is the most critical ( I found this after much experimentation ) A good one here dictates how good the overall output is . Presently it's a GE valve from the 50's but I have a few old mullards I like to put in sometimes!

The clear Kt66's are reproduction ones the grey one and black one are ones i accquired in a lot that i thought were broken but to my susprise they worked - I can't really tell the difference in sound between the old and new!

The output 'A' and 'B' (you can see the 'A'in one of the pictures) is painted on and took an age to get right !!

http://img163.imageshack.us/img163/7366/dsc02364z.th.jpg (http://img163.imageshack.us/i/dsc02364z.jpg/)

http://img263.imageshack.us/img263/474/dsc02370bp.th.jpg (http://img263.imageshack.us/i/dsc02370bp.jpg/)

http://img260.imageshack.us/img260/3086/dsc02362h.th.jpg (http://img260.imageshack.us/i/dsc02362h.jpg/)


here's a picture of my beresford with her top off very sexy!!
I have upgraded al the 100uF and 47uF caps only the 220uF 's to go the sound is a little better . I intially changed the op-amp but took it out to try the old one again I must really put the top on it again(well once the other caps are changed!)

http://img189.imageshack.us/img189/9853/dsc02371p.th.jpg (http://img189.imageshack.us/i/dsc02371p.jpg/)

here's a bit of a close up of the cap upgrades!

http://img683.imageshack.us/img683/6976/dsc02376r.th.jpg (http://img683.imageshack.us/i/dsc02376r.jpg/)

I use a simple tone control which i built. at present i need something interesting to put it in any ideas???
http://img513.imageshack.us/img513/2932/dsc02372p.th.jpg (http://img513.imageshack.us/i/dsc02372p.jpg/)

the leads are all home made from SKY satelitte co-axial . I coudn't believe how much so-called audio cables were throttling my bass response in my setup, the difference was night and day and I would advise people to be very careful with leads they could be holding back your whole system!

at the minute i'm using my old trusty Marantz cd52 Mkii but this will be upgrade to a tweaked phillips cd950 just as soon as i get the time to transform it into a better transport(hopefully over xmas)

my homemade speakers are here , I haven't given them a paint job just yet! I'm still deciding on the colour (any suggestions?) They are 8 inch full range drivers witha frequency response of about 44Hz-28khz so no need for multiple speakers and nasty signal distorting crossover networks! they are only rated to about 30W but in this enclosure they have an efficency of about 106dB/W ( my monitor audio's were about 95)
The enclosure is about a metre high - these are huge speakers !!But Very very clear!

http://img245.imageshack.us/img245/8972/dsc02375l.th.jpg (http://img245.imageshack.us/i/dsc02375l.jpg/)

As i Finally get them finished i'll post more pictures here!

Some peope may have noticed this lurking in the background of other pictures! My tascam 1/4 inch reel to reel player !!!
What a bit of Kit

http://img693.imageshack.us/img693/9020/dsc02374w.th.jpg (http://img693.imageshack.us/i/dsc02374w.jpg/)

Its presently not in use due to excessive hiss but i reckon thats the power caps, which are probably as old as me, and are on the list of things to do!!
It gets the girlies going !!

Now for the bit of kit that forms the back bone of my whole system it is valued very highly by some corners of the hi fi fraternity ! For me I can't remember what my system sounded like before but with it in it still sounds great plus this offers surge protection so its staying!!
Yep some of you might have guessed by now but its a mains conditioner(home made of course)!
PLEASE PEASE DON'T TRY THIS AT HOME IF YA DON'T KNOW WHAT YOU'RE DOING IT HAS THE POTENTIAL (excuse the pun) TO KILL!!!!!!!!!!!!!!!!!!!!!!!!!!!!

what's in it? 10 varistors for surge protection , balanced inductors and caps networks for RF filtering ! All the outlets are switched live and neutral (double pole) -why? This is a must for filtering-any piece of equipment, when not in use, can be isolated completely from the network - any one using a mains filter should unplug anything not in use as it will affect the overall performance of the filtering .

http://img693.imageshack.us/img693/9145/dsc02378u.th.jpg (http://img693.imageshack.us/i/dsc02378u.jpg/)

Well folks there it is my system - its definitely not finished yet - I still have my 6SN7GT(valve) based pre-amp to reassemble but the beresford is doing that function at the minute and I have my cd950 to tweet! I have a pc which i'm going to turn into a media centre soon playin lossless files but time is always the limiting factor ! I would be glad of some pointers, comments! And can someone tell me what colour to paint my speakers???

DSJR
14-12-2009, 17:42
Looks good :) Glad you enjoy the DIY side of things...

I can go one better than satellite cables -

http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF0606.jpg

Ecoflex 10! Wonderful stuff but a pig to weld into a phono plug :)

Puffin
14-12-2009, 18:02
I use a simple tone control which i built. at present i need something interesting to put it in any ideas???



Try a food warmer. Sainsburys £3.99!

http://i73.photobucket.com/albums/i239/saxonsex/Rightspreed001.jpg

Jonboy
14-12-2009, 18:02
Very nice, i have been toying with getting one of those st70 kits myself, American i take it, the original st 70 with el34's is a very nice sounding amp but with kt66's, does it sound better?
I reckon you don't have kids around with all those open circuits:stalks:

Rare Bird
14-12-2009, 18:26
Very nice, i have been toying with getting one of those st70 kits myself, American i take it, the original st 70 with el34's is a very nice sounding amp but with kt66's, does it sound better?
I reckon you don't have kids around with all those open circuits:stalks:

You can still buy the Dynaco kits both the stereo & mono's the transformers are Hamonds so will be pretty good, last i saw they worked out expensive.IMHO the kit chassis need updating abit.

jcgrant
14-12-2009, 19:20
wow i amazed at the replies so far !! first and foremost no ankle biters(kids) whatsoever!! the ony bit of kit i have to worry about shocking kids with is the amp( i haven't had any drunk mates touch it yet either ) , the tone control is way low voltage and the beresford is about 10V max!!

I like the sainsburys/tesco's idea going very shortly

JonBoy the amp is from this guy
http://bob01605.50webs.com/
price is variable i susppose with exchange rate and there would be customs charges etc. Not as expensive as some kits you can get but i thought it might be a good starting point
good after sales service from this guy as well!He has totally redesigned the original ST70 giving it more beeefy trannies etc.

I see the audio world in two ways either spend loadsa money and get a half decent system , spend a lot less money and build it yourself - get an equal or better system !! And its fun!

Jonboy
14-12-2009, 19:35
You can still buy the Dynaco kits both the stereo & mono's the transformers are Hamonds so will be pretty good, last i saw they worked out expensive.IMHO the kit chassis need updating abit.

This is where i found the kits
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=380060348206&ssPageName=STRK:MEWAX:IT

I quite fancy a pair of these,

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=380152923340&ssPageName=STRK:MEWAX:IT

Jonboy
14-12-2009, 19:39
JonBoy the amp is from this guy
http://bob01605.50webs.com/
price is variable i susppose with exchange rate and there would be customs charges etc. Not as expensive as some kits you can get but i thought it might be a good starting point
good after sales service from this guy as well!He has totally redesigned the original ST70 giving it more beeefy trannies etc.

I see the audio world in two ways either spend loadsa money and get a half decent system , spend a lot less money and build it yourself - get an equal or better system !! And its fun!


Cheers for the link James, and a nice annalergy (i think thats the right word)on HIfi

Spectral Morn
14-12-2009, 20:28
Hi James


Welcome to AOS.


And someone from NI that I don't know....I think, though we may have met at some point.

Very interesting gear, love the idea of DIY, but I know better than to pick up a soldering iron for more than speaker repairs or interconnects.

I would love to hear your set up some time as you could mine...if you are interested.

Love the reel to reel...I have a Revox A77 and B77.


Regards D S D L

aquapiranha
17-12-2009, 19:44
Hi James and welcome. Some lovely kit there. Nice R2R, if I see another one I am going to throw something! arrghhh missed out on a PR99 last night, went for £70 odd quid.

:)

Spectral Morn
17-12-2009, 19:48
Hi James and welcome. Some lovely kit there. Nice R2R, if I see another one I am going to throw something! arrghhh missed out on a PR99 last night, went for £70 odd quid.

:)

Only has balanced (XLR) ins and outs. You can use adapters, but there can be losses + the output voltage level can be 3 to 5 volts..which can overload some pre-amplifier in puts.


Regards D S D L

aquapiranha
17-12-2009, 19:57
Hi Neil. Yeah he did mention that in the add. the Rane X-over I am using has XLR! so i wasn't too worried about it. Anyway, as I mentioned to you the other day I will have to wait till hell freezes over lol.