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Psvane 12AX7 questions -

ceylon said:
ive used em (psvane art series) in phono. a good pair is neither microphonic nor noisy. clear, smooth. i still cant get a straight answer on whether or not the art series and red print are the same tube.

EH7025 is a good one as well. quiet.
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I've never tried the EH 7025. Are they true 7025 tubes, with spiral-wound heater filaments?

The nice Sovtek 12AX7LPS are spiral wound.

Thanks!
 
Mr Boochie said:
I've never tried the EH 7025. Are they true 7025 tubes, with spiral-wound heater filaments?

The nice Sovtek 12AX7LPS are spiral wound.

Thanks!
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that i dont know. never looked, but i assumed so. although throwing around tube model #s willy nilly is pretty popular, i thought all those russian tubes had spiral wound filaments.
 
ceylon said:
that i dont know. never looked, but i assumed so. although throwing around tube model #s willy nilly is pretty popular, i thought all those russian tubes had spiral wound filaments.
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Well, they used to be all advertised low-noise. And ppl online would confuse that with spiral wound filaments.

AND, spiral wound doesn't always guarantee low-noise. How well the tube is constructed prolly counts more.

Old-school, plain wound TFK ECC83 are pretty darn quiet tubes. :)
 
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Lavane said:
I've considered trying the frame grid JJ's. But I just don't have anything at the moment that uses 12AX7's. I am building another preamp at the moment that uses 12AX7's, so I might give them a try. I had held off starting the preamp until I finished a tube phono preamp, but I ran into a snag getting a tool I needed. It got lost in the mail, and I had to order another one.
The only suppliers for this particular tool that I could find was China and Germany.
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If you don't mind me asking --- which tool is that?

Thanks!
 
A 34mm Forstner bit. Most are in std. inches. Here in the states. A 1 3/8" I have is just a bit too big. I'm mounted them from the back side, most people.mount these type from the front showing the square flange with the mounting holes. It's the easiest, but they look better with just the round bezel showing.
 
Mr Boochie said:
I've never tried the EH 7025. Are they true 7025 tubes, with spiral-wound heater filaments?

The nice Sovtek 12AX7LPS are spiral wound.

Thanks!
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Thay Sovtek LPS tube probably sounds good but that one is a long plate 12AX7 - and I suspect that it’s microphonic. The other Sovtek 12AX7’s (WA, WB and WC) are all shorter plate versions and I suspect don’t sound as rich as the LPS but probably are quieter.

Lots of new 12AX7 choices right now… If I knew that the JJ short plates sound good, I’d order some of those; their price is right.
 
MisterDK said:
Thay Sovtek LPS tube probably sounds good but that one is a long plate 12AX7 - and I suspect that it’s microphonic. The other Sovtek 12AX7’s (WA, WB and WC) are all shorter plate versions and I suspect don’t sound as rich as the LPS but probably are quieter.

Lots of new 12AX7 choices right now… If I knew that the JJ short plates sound good, I’d order some of those; their price is right.
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Got to buy them from a dealer that tests them for noise. In my experience, ther 12AX7LPS were no noisier, than other 12AX7s.

If quiet is what you are after and your unit can tolerate a bit less mu... the US made mil spec 5751 may be worth a look.

Some of the finest 9-pin minis ever made are 5751s. :thumbsup:
 
Mr Boochie said:
Got to buy them from a dealer that tests them for noise. In my experience, ther 12AX7LPS were no noisier, than other 12AX7s.

If quiet is what you are after and your unit can tolerate a bit less mu... the US made mil spec 5751 may be worth a look.

Some of the finest 9-pin minis ever made are 5751s. :thumbsup:
Click to expand...

I don’t want to play with NOS, US made - unless they truly are NOS and priced fairly..

I have a pair of real NOS, English made, Westinghouse 12AX7’s in this phono preamp I just built but those are more microphonic than the Chinese Shuguang in there with ‘em. I moved them in all positions to check. In V1 the Chinese tube is least microphonic!
This still sounds excellent though, despite tubes being microphones..

I couldn’t ID that pair from the mfg. code other than they appear to be made by one of the Mullard plants - and there were quite a few different ones. Maybe someone here will recognize ‘em…

IMG_6406.jpeg
 
Mr Boochie said:
Well, they used to be all advertised low-noise. And ppl online would confuse that with spiral wound filaments.
Click to expand...
sure. the spiral filament reduces hum in some circuits.
Mr Boochie said:
AND, spiral wound doesn't always guarantee low-noise. How well the tube is constructed prolly counts more.
Click to expand...
but noise and hum are 2 different things.
Mr Boochie said:
Old-school, plain wound TFK ECC83 are pretty darn quiet tubes. :)
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dam strait
 
MisterDK said:
I don’t want to play with NOS, US made - unless they truly are NOS and priced fairly..

I have a pair of real NOS, English made, Westinghouse 12AX7’s in this phono preamp I just built but those are more microphonic than the Chinese Shuguang in there with ‘em. I moved them in all positions to check. In V1 the Chinese tube is least microphonic!
This still sounds excellent though, despite tubes being microphones..

I couldn’t ID that pair from the mfg. code other than they appear to be made by one of the Mullard plants - and there were quite a few different ones. Maybe someone here will recognize ‘em…

View attachment 3068533
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i cant tell from here. can you post several clear pics? can u post pics of the manufacturers codes?
 
MisterDK said:
I don’t want to play with NOS, US made - unless they truly are NOS and priced fairly..

I have a pair of real NOS, English made, Westinghouse 12AX7’s in this phono preamp I just built but those are more microphonic than the Chinese Shuguang in there with ‘em. I moved them in all positions to check. In V1 the Chinese tube is least microphonic!
This still sounds excellent though, despite tubes being microphones..

I couldn’t ID that pair from the mfg. code other than they appear to be made by one of the Mullard plants - and there were quite a few different ones. Maybe someone here will recognize ‘em…
Click to expand...
You know, tubes are microphonic to a degree by their nature. Components like caps can be, too.

Some folks say a dead-quiet, completely non-microphonic tube lacks the inherent analog "sparkle," that so many Tubeheads love over solid-state.

The 5751 is just an idea. If a good triple mica, black plate Sylvania or GE shows up, at a good price --- think about it. :idea:
 
Mr Boochie said:
Wow! You using that to "punch" some holes in the chassis?

No wait, it's for wood.
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I use them on aluminum too. I had a thick face plate and had to relieve the back side so the shafts of the selector and volume control could get through to the front so I could get the nuts on them. I had to do the same for the pilot light.
 
Lavane said:
I use them on aluminum too. I had a thick face plate and had to relieve the back side so the shafts of the selector and volume control could get through to the front so I could get the nuts on them. I had to do the same for the pilot light.
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This is the issue that I front with my ARC SP3A1 - @Lavane : can you explain / show me how you manage that glitch ? ;)

T
 
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