My Valve Itch phono stage making lovely music...
Hi All
My valve itch phono is now completed and making some lovely music.
I used two 150C2 (0A2) gas regulators supplied by an Ixys 10M45S CCS at 25mA for the 300V supply.
The power supply is a valve rectified CLCL in a separate case with an umbilical cable with Mil-spec connectors. The Phono stage is built in an old surplus case that originally housed a defunct Pye Telecom transmitter.
The input audio stage 6N2P is a 1968 vintage with double top mica's the output is a Sylvania VT231.
The input stage 6N2P's are mounted on a damped spring suspension (a bit of overkill perhaps). The MC step up transformers are Sowter. The output caps are Russian PIO KBG caps.
Its sounds superb, totally silent with no input and no hum.
Hi All
My valve itch phono is now completed and making some lovely music.
I used two 150C2 (0A2) gas regulators supplied by an Ixys 10M45S CCS at 25mA for the 300V supply.
The power supply is a valve rectified CLCL in a separate case with an umbilical cable with Mil-spec connectors. The Phono stage is built in an old surplus case that originally housed a defunct Pye Telecom transmitter.
The input audio stage 6N2P is a 1968 vintage with double top mica's the output is a Sylvania VT231.
The input stage 6N2P's are mounted on a damped spring suspension (a bit of overkill perhaps). The MC step up transformers are Sowter. The output caps are Russian PIO KBG caps.
Its sounds superb, totally silent with no input and no hum.
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Very vintage aesthetic build, very nice. You obviously have made enough diy valve gear before. Don't know about the springs bcs this valve type was particularly non microphonic at least in the batch we got back then, but can't hurt and adds some meccano appeal. What other phono you got and what's the system it plays in?
Hi Salas
Yes I agree, the springs are probably not really required, but I had the room to do it, so why not! Vinyl front end is either Linn LP12, Ittok LVII, Ortofon MC25FL or Garrard 401, home made air bearing tone arm, Ortofon MC25FL, currently using the LP12 as I just had it rebuilt.
I have a DIY copy of the World Audio Designs Phono II stage.
I also have a Cambridge Audio 640P which I totally recapped and changed the opamps in, I also threw away the original power supply and replaced it with an R-core transformer. The Cambridge is a quite remarkable phono stage now, not easily outdone.
The phono runs into a DIY TVC with Sowter 9335 transformers. The TVC drives a Either a DIY parafeed single ended 2A3 amplifier (parallel 6N1P into Hammond 126C interstage TX's driving EML Mesh plate 2A3's Sowter plate chokes and output transformers) or a DIY SE45 (Trioded D3a into Hammond 126A Interstage TX's driving 45's with AE Europe amorphous output TX's).
Speakers are Mauhorn V's with Lowther DX4 drivers and Fostex T90A super tweeters.
Now those are good news... What type of opamps are you using now ?
BTW.... Splendid work on the Itch !!!!
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At the risk of hijacking your excellent thread!
http://www.diyaudio.com/forums/analogue-source/120191-cambridge-audio-640p-2.html
Hi again D-D
Can you tell me...?
...what's the deal with the Russkie PIO's on your outputs ?
Just guessing...
...but I figure you might have tried some PP's here as well...
...& ended up liking the ex-Soviet military hardware the best.
???
What's the story ( if any )...
...love to know your thoughts on the general cap choice in your build.
Si.
Can you tell me...?
...what's the deal with the Russkie PIO's on your outputs ?
Just guessing...
...but I figure you might have tried some PP's here as well...
...& ended up liking the ex-Soviet military hardware the best.
???
What's the story ( if any )...
...love to know your thoughts on the general cap choice in your build.
Si.
Hi
When I built my parafeed 2A3 amplifier I tried many output coupling capacitors and the Russian KBG PIO were the the best I found.
Nearing completion!
I think its been two years in the making (ill health restricts me somewhat) but yesterday I fired up my itch attached to its final home for the first time. Hurrah! I did realise though that I had forgotten to include an earthing point for the tonearm so I attched to the main amp instead for the momenbt. My question is what is the wisdom here. Is there a clever trick that mimimises hum for tonearm earth? Should I create an earth point outside my itch box for this and attempt to isolate this from the case but feed it directly to the main earth using star config or to the furthest end of the bar earth away from all the heavier items? Or is there anything clever that I am missing here?
I will throw some piccys up soon.
I think its been two years in the making (ill health restricts me somewhat) but yesterday I fired up my itch attached to its final home for the first time. Hurrah! I did realise though that I had forgotten to include an earthing point for the tonearm so I attched to the main amp instead for the momenbt. My question is what is the wisdom here. Is there a clever trick that mimimises hum for tonearm earth? Should I create an earth point outside my itch box for this and attempt to isolate this from the case but feed it directly to the main earth using star config or to the furthest end of the bar earth away from all the heavier items? Or is there anything clever that I am missing here?
I will throw some piccys up soon.
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Revoli, nice. Concluded after some time to an individual & interesting compact build. Can you share some info about the system it serves in?
Yes the build was somewhat of a challenge, having decided on a two box system and having a specific space to fill size became an issue. The upside is it keeps all wires nice and short. The downside is when I change the cartridge getting to the input resistor will be a job. Never mind, its worth it. This is feeding from my Rega Planar 3 with RB200 tonearm and high output Dynavector 10x4. So I have a 3k3 resistor at input which seemed to be the happiest sound. The amp is a World Audio Design 6550 which is great feeding my ever loved Heybrook HB1 speakers. All very satisfactory. And the vinyl.....
Everything from the classics to Nickleback and beyond, a lot of acoustic guitar stuff, JJ Cale, etc. Next project? Maybe a sceond system for my office/workshop as I have a spare Mitchell Focus One deck and SME tonearm sitting in the loft....
Everything from the classics to Nickleback and beyond, a lot of acoustic guitar stuff, JJ Cale, etc. Next project? Maybe a sceond system for my office/workshop as I have a spare Mitchell Focus One deck and SME tonearm sitting in the loft....