Good 12ax7

[SY]

Nothing like the good old "pencil test".It instantly shows the "master valve"

Exactly so. Tells you how microphonic and at what frequencies.

 

[Panicos K]

It takes a poor circuit (guitar amp?) for a simple change of valve to produce a significant change in frequency response. Valve reviews based on guitar amps tell us very little about how the valve will behave in a well-designed hi-fi amp. I suspect that in some cases a change in distortion is being misinterpreted (by ear) as a change in frequency response.

If you are refering to my post about the pencil test,I didn't mean guitar amp,but a phono stage (mostly) and then surely a hifi amp.

 

[DF96]

No, sorry, I was referring to review in one of the links.

By pencil test, do you mean test for microphonics by tapping with a pencil?

 

[Panicos K]

No, sorry, I was referring to review in one of the links.

By pencil test, do you mean test for microphonics by tapping with a pencil?

Yes.

 

[migkiller1971]

I can't get away from my 12ax7 Ribbed Telefunken. They are just so detailed. I've tried Amperex Bugle Boy, New JJ, matsushita, new tung-sol, I still haven't tried any mullard's in 12ax7.

 

[Rockmore]

Must have been asked here many times.

Can you name some good online tube retailers?

Looking for some 12ax7's.


Thanks, Gene

Captain Bob's Tube Emporium

 

[GeneZ]

The JJ ECC83s? Triode Electronics.

Are the ECC83's the European version of the 12ax7? I need 12ax7's.

 

[migkiller1971]

Are the ECC83's the European version of the 12ax7? I need 12ax7's.

yes

 

[SY]

Same tube, different part number. Absolutely equivalent.

 

[DF96]

These days the ECC83 and 12AX7 can be regarded as exact equivalent. I believe in the early days there was a difference: at first only ECC83 had a low-hum spiral heater but the 12AX7 soon adopted this too. Some modern versions (whatever they are labelled) may have a conventional heater, which may be partly why DC heating is now more popular.

 

[GeneZ]

OK... I have a British hybrid by Roy Grant. The preamp runs ECC88 tubes. Anyone familiar with these?

 

[SY]

Yes.

 

[ruffrecords]

If you want lowest distortion I would recommend the LPS (long plate) version by Sovtek. These measure significantly better than any other 12AX7 type I have tried.

Cheers

Ian

 

[GeneZ]

Yes.

Can you tell me anything as to why some chose the ECC88's? I found a blurb saying they were quieter than 12ax7's.

 

[TheGimp]

The E88CC and ECC88 were/are low noise "SQ" (Special Quality) tubes.

http://www.mif.pg.gda.pl/homepages/frank/sheets/009/e/E88CC.pdf

 

[GeneZ]

The E88CC and ECc88 were/are low noise "SQ" (Special Quality) tubes.

http://www.mif.pg.gda.pl/homepages/frank/sheets/009/e/E88CC.pdf

Thank you. Its apparent that Roy Grant did not scrimp.

The preamp section runs six ECC88's. I am wondering if all are needed to be plugged in since I no longer use the phono section.

 

[kevinkr]

Thank you. Its apparent that Roy Grant did not scrimp.

The preamp section runs six ECC88's. I am wondering if all are needed to be plugged in since I no longer use the phono section.

I recommend you leave as is as removing them is likely to affect supply voltages.

 

[kevinkr]

Can you tell me anything as to why some chose the ECC88's? I found a blurb saying they were quieter than 12ax7's.

Much higher transconductance, with resulting lower rp results in a significantly quieter amplifying device. The lower rp allows the use of smaller plate load resistors and lower impedance EQ networks which also help noise performance.

 

[Joshua_G]

If you want lowest distortion I would recommend the LPS (long plate) version by Sovtek. These measure significantly better than any other 12AX7 type I have tried.

Cheers

Ian

I second the Sovtek 12AX7 LPS.

 

[GeneZ]

I recommend you leave as is as removing them is likely to affect supply voltages.

Its good to be here (once again).


Thank you for your answer.

Gene