Gyraf Pultec finished (Shopping list included!)

[white noise]

Hi,

I saw that you can use either ECC88 tubes or 6DJ8 tubes for the Pultec PEQ1A EQ (SRPP-based version). Which of the two do you recommend me? Thanks in advance!

 

[alk509]

[quote author="white noise"]I saw that you can use either ECC88 tubes or 6DJ8 tubes for the Pultec PEQ1. Which of the two do you recommend me?[/quote]

ECC88 and 6DJ8 are the same tube. You may want to also try their 'improved' versions, E88CC/6922. And some people like to put a 6N1P in place of a 6DJ8/6922/ECC88/E88CC. Be aware, however, that the 6N1P will draw .6A of heater current, so plan accordingly.

They can all be had for cheap, so don't be afraid to experiment!

Peace,
Al.

 

[white noise]

Thanks for the advice alk509 / Al, I appreciate that! :thumb:

Do the 'improved' versions (E88CC/6922) sound better than the original ECC88/6DJ8 tubes, or just different? And how about the 6N1P, does it have any characteristic differences sound wise, compared to the the ECC88 and 6DJ8 tubes? I am going to use the pultec for sound design so I don't need the cleanest sound, but I am looking for warmth.

Best wishes, David.

 

[clintrubber]

[quote author="white noise"]Thanks for the advice alk509 / Al, I appreciate that! :thumb:

Do the 'improved' versions (E88CC/6922) sound better than the original ECC88/6DJ8 tubes, or just different? And how about the 6N1P, does it have any characteristic differences sound wise, compared to the the ECC88 and 6DJ8 tubes? I am going to use the pultec for sound design so I don't need the cleanest sound, but I am looking for warmth.

Best wishes, David.[/quote]

As I understood it these 'reversed' type-no's were about quality (sturdyness, life), so not necesarrily about improved parameters.

The SQ-databook does not provide a compact explanation however about the difference with the normal ones, so it's hard to tell if these are actually 'better' tubes or just more guaranteed tubes. Either/or, the result will be about the same :wink: Hope someone knows the 'real' story.

The Philips-ones I've seen are labelled SQ (Special Quality)
and have fancy gold-coloured pins.

 

[white noise]

At the local tech store here in Holland they only sell the Sovtek 6922 tube, is this a good tube for the Pultec PEQ1A EQ (SRPP-based version)? I saw there are some different types and brands of 6922 tubes out there (for instance the much recommended JAN-Philips 6922 Low Noise) and other possible substitutes. Is the Sovtek any good or should I look for an other brand? Thanks in advance!

 

[clintrubber]

[quote author="white noise"]At the local tech store here in Holland they only sell the Sovtek 6922 tube, is this a good tube for the Pultec PEQ1A EQ (SRPP-based version)? I saw there are some different types and brands of 6922 tubes out there (for instance the much recommended JAN-Philips 6922 Low Noise) and other possible substitutes. Is the Sovtek any good or should I look for an other brand? Thanks in advance![/quote]
Depending on whether you want it as good as possible right away or get things going & eventuall swap later on, www.easymeasure.nl sells suited tubes (Russian).
www.marktplaats.nl etc usually has ECC88/PCC88-types as well.
That's what I did: bought some NOS Siemens/Philips PCC88-types from marktpl. & did a one-resistor adjustment in the heater supply.

BTW, I realize this was an alternative suggestion and not an answer to your question :wink:

What kind of frontpanel are you using BTW ?

Bye,

Peter

 

[white noise]

Thank you Peter for your info, strangely I hadn't thought about marktplaats.nl. for a tube, that is a good idea. I see there are a lot of different ECC88/PCC88 and 6922 tubes out there, some very expensive (250 USD) others quite cheap (7 USD), but I was wondering does anybody know the differences in sound and quality? Is the Sovtek 6922 tube a good tube or should I look for something else? I read somewhere that Avalon uses Sovtek tubes, but I don't know if they use the 6922 and if that says anything at all.

Peter wrote: What kind of frontpanel are you using BTW?

I am still thinking about that. I thought I would let Schaeffer (see link) do it, but I don't know if they only print or also engrave. I really like those old school designs with big knobs, so the 19" rack has to be 2U high at least.

http://www.schaeffer-apparatebau.de


Best wishes, David.

 

[clintrubber]

[quote author="white noise"]Thank you Peter for your info, strangely I hadn't thought about marktplaats.nl. for a tube, that is a good idea. I see there are a lot of different ECC88/PCC88 and 6922 tubes out there, some very expensive (250 USD) others quite cheap (7 USD), but I was wondering does anybody know the differences in sound and quality? Is the Sovtek 6922 tube a good tube or should I look for something else? I read somewhere that Avalon uses Sovtek tubes, but I don't know if they use the 6922 and if that says anything at all.[/quote]
I was wondering about that as well, and you'll have seen those webpages about all those kings/brands/etc as well. I'm simply not going to spend that kind of money on a tube - at least not before having tried something more ordinary so I have some reference.

And has been said on this site before, PF86, PCC88 etc etc i.s.o. their E-brothers is fine if you want to take the little trouble of adapting the heater-supply and prices become sane again. ECC88 can be had for normal prices as well of course, but as it happened I ran into those P-types before I had stuffed the heater-section-resistors.

Peter wrote: What kind of frontpanel are you using BTW?

I am still thinking about that. I thought I would let Schaeffer (see link) do it, but I don't know if they only print or also engrave.

http://www.schaeffer-apparatebau.de


Best wishes, David.

As I understood it (and I'm about sure) they engrave everything and you have the option of filling it or not. But say an engraved black panel with the alu-lettering looks fine to me, even better than say having it filled for white letters.

I really like those old school designs with big knobs, so the 19" rack has to be 2U high at least.

I'm totally with you, same preference here. I have now collected some old black bakelite-knobs (mid & large-sized) from old Philips measurement gear for two 2HE EQs. So if we have alike knob-sizes maybe we should keep in touch :thumb:

I need to toy around with how I want the panel - I'd start from the Gyraf-design but I like that Pultec-blue and some freq-indications like the orig Pultec (adapted for the new freqs) etc.
I haven't looked yet how much shipping & handling for a Schaeffer-jobbie would be in total.
With support-your-local-small-stores-you'd-hate-to-see-going in mind I also asked around locally and here they're asking around EU 45 for the first and half that for the second panel (own pre-bought panels).

Either way, some playing around with the Schaeffer-program is in order to give me a further ideas. As I understood it you're more or less stuck with the available Schaeffer-colours (they have not really a suited blueish colour I'd say), since painted panels won't work well.

Bye,

Peter

 

[radiance]

Powder coated panels work, but are also a little expensive....

 

[white noise]

Radiance wrote me that Schaeffer engraves and also drills the holes. For an amount in the neighborhood of 50 Euro, I think that is quite a reasonable price for the job. It would be really convenient too if they drill the holes. Someone told me, black frontplates stay the best over time, so I guess I will be conservative and stick with the good, old black design, which also fits nicely with my Macbeth M3X synth I really like what Greg did with his G4000 (see link):

http://www.groupdiy.com/index.php?topic=7564&postdays=0&postorder=asc&start=15#img_1763

Those old black bakelite-knobs (mid & large-sized) from old Philips measurement gear, you describe Peter, sound really superb. I am also totally with you concerning those freq-indications like on the orig Pultec, although I can only seem to find pictures with only scales and no numbers with the scales. I would like to do my Pultec with numbers with the scales. As you wrote Peter, it would be nice if we could stay in contact.

By the way, again thank you Radiance for all the info! :thumb:


All the best, David.

 

[white noise]

Does anybody have any experience with the Amperex 'Bugleboy' ECC88/6DJ8 tube and the Telefunken ECC82 / 12AU7? I read that they are among the best vintage tubes, especially the Telefunken should be great, could anybody expend on that? Thanks in advance!


Best wishes, David.

 

[cactus]

about the partslist - must all the film caps be rated for 250V? i see from the pictures, yours had to be bent up pretty good to fit.

will some 25V or 35V films be ok?

thanks

 

[Purusha]

[quote author="ChuckD"]I think it was about 61.00 USD.
All of that is in the Parts List guys....

Total price of the EQ = $377.00

Cheers,

Chuck[/quote]

$377.00 for the stereo version?

 

[nicodjhouse]

hi guys!

i'm beginning to build a pulteq srpp eq, and i don't know what inductors to choice? to smallest or highest Q? i think it's the smallest, but i would accept any help !

http://fr.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=1077047&N=0

http://fr.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=432283&N=0

thanks !

 

[gyraf]

..prefer lowest DC resistance..

 

[CJ]

Anyone know the Torwico p/n for the suspected Pultec inductor?
If I could get some of those cores.......

 

[nicodjhouse]

would a toroid transformer work as the second transformer (12v -> 220v?), I'm also trying to put the tube in front of the rack (viewable with a little plastic glass)... Will I get some electronmagnetics problems to use cables??

thanks

Nico

 

[Gilbert]

Could you tell me how you wired the Triad Transformer? cant tell from the picture. Thanks

 

[Siegfried Meier]

I would also like to know more about the Triad transformer. I've got all the datasheets, and I'm pretty close to figuring it all out. Here goes:

From Amveco - Blue and Red connected go to 15V of PCB, Green and Brown connected go to 15V of PCB

To Triad - Red 12V of PCB goes to "Pin 2 of Triad??", Black 12V of PCB goes to "Pin 1 of Triad??", then pin 3 and 4 are connected somehow and I can't see that.

Pin 5 of Triad goes to 240V in of PCB, Pin 6 of Triad goes to 240V of PCB

The only confusing thing is those extra black wires on pins 3 and 4 of the Triad, as I can't see from the pic where it goes. Any of this making sense?

Thanks,
Sig

 

[louder]

Hi
i`ve done it.
no smoke and no noise.
this eq has lots of bass,and the highest frequencies have good definicion.
the only strange thing it`s that i connected the pots the wrong way:the boost pot`s when cw,cut;ccw they boost.
when i get more time,i`ll tell ya more.
ps:i added a 10k resistor in series to the 3k3 resistor,which got me 260v in the e88cc(valvo) plate.
the heaters,got 6,1v,which i think it`s okay.
once again,thank you so much Jakob.
best regards
pedro