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Re: PI tube question

Posted: Mon Feb 14, 2011 1:33 pm
by menace2u
Hamtone just hit the LOTTERY!!!!!!!!!

Re: PI tube question

Posted: Tue Feb 15, 2011 12:17 am
by Hamtone
Unfortunately the rca's were no good. But the telefunken in v1 is ridiculous. Only problem with it is, it is souch touch sensitive it really shows my sloppy playing. I put the mullard ax7 in the pi and that really makes the amp blossom. The mullard is a bf something something, the screen print is worn. There is another mullard which turned out to be an au7 that I put in my tube driver which smokes any ax7 and at7 I have ever had in it. There's also an amperex which was good in v1 but nothing like the telefunken. Again with these tubes I found another increase in volume and high end clarity.. My ears actually hurt and I did not turn the amp up. I definitely will be getting a 4x12 to enhance the low end.

I will still tale some snaps j
ust for the sake of them being old tubes.

Re: PI tube question

Posted: Tue Feb 15, 2011 3:03 pm
by Hamtone
I wonder if what i am hearing is an increase in presence giving the impression of it being louder :?: Its certainly a high end clarity that has improved with these tubes over the nos ones I had in it before.

Re: PI tube question

Posted: Tue Feb 15, 2011 3:31 pm
by OldSchoolDave
Hamtone wrote:I wonder if what i am hearing is an increase in presence giving the impression of it being louder :?:
Could very well be.

With the same power tubes, output should be roughly the same (when maxed, that is).

Dave

Re: PI tube question

Posted: Sun Feb 27, 2011 5:04 pm
by ak-47
While on the subject of tube lotteries...

I picked this bunch up last week for about $15US / €11Euro. I know some of the types and their uses but not all if anyone cares to enlighten me?

From left to right:

PC86 521137 (any ideas what this is?)
Motorola 12AX7A
Ei Yugoslavia PCH-200
RFT PCF802
Motorola 12AX7A
Mullard EF89 (used in tv’s?)
Mullard M8162 12AT7WA/WB CV4024 KB/D x3 pieces (yeah... those ones :D )
Mullard PF86

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Re: PI tube question

Posted: Sun Feb 27, 2011 5:16 pm
by OldSchoolDave
If flashing is an indication, those Motorolas are pretty well used up. But, you got MORE than your money's worth out of the Mullard M8162's.

Dunno about the other species. The screened plates on the EF89 are kinda cool.

Dave

Re: PI tube question

Posted: Mon Feb 28, 2011 1:31 pm
by ak-47
Thanks Dave! I can't wait to try my mullards out in P1 (that is the best place huh?)

Do I understand right that if the motorlas flash on startup they are pretty toasted? Or do you mean they might be bad by your visual inspection?

Re: PI tube question

Posted: Mon Feb 28, 2011 1:38 pm
by OldSchoolDave
ak-47 wrote:I can't wait to try my mullards out in P1 (that is the best place huh?)
Absolutely! You'll be glad you did :) .
ak-47 wrote:Do I understand right that if the motorlas flash on startup they are pretty toasted? Or do you mean they might be bad by your visual inspection?
Sorry - I was not talking about power-up flash. I was referring to the silvery flashing at the top of the tube. It's pretty transparent on those Motos. Some manufacturers exhibit less flashing than others, but those are thin and the edges are fuzzy (new tubes generally have crisp flashing edges). It's a semi-scientific judgement at best. Plug them in and give them a try.

Dave

Re: PI tube question

Posted: Tue Mar 01, 2011 10:34 pm
by ak-47
OldSchoolDave wrote:Sorry - I was not talking about power-up flash. I was referring to the silvery flashing at the top of the tube. It's pretty transparent on those Motos. Some manufacturers exhibit less flashing than others, but those are thin and the edges are fuzzy (new tubes generally have crisp flashing edges). It's a semi-scientific judgement at best. Plug them in and give them a try.
Ok, thanks.. I did not know that. I will try to mess around later this week with the mullards and motorolas and let you know what I think.

The PC 86 is apparently an RFT... as these are a 9 pin triode, can they substitute for a 12ax7 or 12at7? ... I know so little about tubes :oops:

Re: PI tube question

Posted: Wed Mar 02, 2011 12:31 pm
by mhuss
ak-47 wrote:The PC 86 is apparently an RFT... as these are a 9 pin triode, can they substitute for a 12ax7 or 12at7? ... I know so little about tubes :oops:
That is a UHF oscillator tube. Two problems (1) there is only one triode inside (unlike the 12A?7 which has two) and (2) The pin-put is completely different.
http://www.radiomuseum.org/tubes/tube_pc86.html

--mark

Re: PI tube question

Posted: Wed Mar 02, 2011 1:51 pm
by ak-47
Thanks for the heads up Mark... After reading around, I am quite sure that once I put one of the M8162's in I won't really be too interested in all that other stuff anyway :mrgreen: