Build Thread:PQD2

[antisleep]

The great thing about DIY is, you can change the resistor ladder to your liking. For the low end, we are not dependent on the whole range of the switch, so just put larger values in per step

Of course. But first my reason for asking (and sorry if this wasn't clear) was to see if this is by design, or if I made an error in my build. Thus "Do other folks experience this?"

 

[MonoCutter]

A long time in the making, but now it's finally done.
This was my first tube project and and i think i'm hooked now.

One thing i learned was, that i will never buy JJ tubes again.
Maybe i can use them as microphones, because they are really good at that.

Thanks for all the help and information in this thread,
Dennis

 

[eltorro84]

hi
i am currently planing my goly pq2 build. hope will get the pcb board from the limited batch soon.
Has anyone files for the faceplate design?
Is it possible to replace the inductors with the g-pultec inductors from don audio?
-Volker

 

[antiehdas]

Hello !

I start getting all the parts for my PQ2 build. And would love to get some help for some of them

1. Iductors

Can someone point me to which one i should get ? and like Volker asked up there, i also heard about the don audio inductors.

2. Round Diode Bridge

Maybe someone got partnumber for that ?

3. matched ECC88

Any hints on where to get them matcheds and for a good price/quality ?

Thanx a lot !!! looking forward to build this thing !

Cheers,

Andreas

 

[JMan]

For the diode bridge, something like this should work.

 

[JMan]

A long time in the making, but now it's finally done.
This was my first tube project and and i think i'm hooked now.

One thing i learned was, that i will never buy JJ tubes again.
Maybe i can use them as microphones, because they are really good at that.

Thanks for all the help and information in this thread,
Dennis

That looks amazing! I'm not familiar with that enclosure, where did you find it?

 

[MonoCutter]

Thank you!
This type of case is common in Europe for electronics and measuring equipment. I think they were originally designed for Eurocards.

Mine is very similar to this one: https://www.distrelec.de/en/subrack...p/11074438?no-cache=true&marketingPopup=false

I bought 3 of them in the past, all had rotary switches, psus and other stuff installed. And i paid around 30,- each.

 

[antiehdas]

hi
i am currently planing my goly pq2 build. hope will get the pcb board from the limited batch soon.
Has anyone files for the faceplate design?
Is it possible to replace the inductors with the g-pultec inductors from don audio?
-Volker

Any luck on the inductors ? i also wrote don audio about the same question. I got everything together now, only inductors and diode bridge missing

 

[MonoCutter]

Any luck on the inductors ? i also wrote don audio about the same question. I got everything together now, only inductors and diode bridge missing

Hi, you just have to check this thread. It's was already asked and answered. For example... check #49 from Gustav, #136 from Murdock

 

[antiehdas]

Hi, you just have to check this thread. It's was already asked and answered. For example... check #49 from Gustav, #136 from Murdock

Thanx ! yes, but not answered what inductor from don audio, or what values to look for at mouser for example, apart of the mH from the partslist.

 

[JMan]

As I understand it, this circuit is identical to the G-Pultec except for being adapted for stereo operation. So, the G-Pultec schematic calls for series inductor values of 22uH, 47uH, 100uH, and 100uH. If you add each step of these values up (series), you get the values for the Don Audio inductor labeled...drum roll..."G Pultec Inductor."

First step: 22uH
Second step: 22+47=69uH
Third step: 22+47+100=169uH
Fourth step: 22+47+100+100=269uH

The reason that these numbers aren't represented in the same way in both places is that with fixed inductors, you are literally using four separate components that each have individual values that are additive in the circuit, whereas with the multitapped inductor you are looking at each tap's total inductance relative to the starting point of the coil.

 

[MonoCutter]

Haha, JMan, you were just a minute faster than me. But i wanted to write basically the same.

 

[MonoCutter]

I used these cheap inductors from Reichelt and they do a good job.

https://www.reichelt.de/stehende-induktivitaet-11p-ferrit-22m-l-11p-22m-p73006.html?&nbc=1https://www.reichelt.de/stehende-induktivitaet-11p-ferrit-47m-l-11p-47m-p73008.html?&nbc=1https://www.reichelt.de/stehende-in...0000-h-5-20-khz-l-11p-100m-p73010.html?&nbc=1

 

[eltorro84]

No updates about the don-audio inducter yet.
The Goly layout uses 4 inductors per channel, 22mH, 47mH, 2x 100mH. I guess depending on the switch pos, some inductors were connected in series.
So it is not a 1:1 replacement when using the don-audio or other inductors.
But i am still waiting for the pcb to arrive to confirm my guessing.

 

[JMan]

No updates about the don-audio inducter yet.
The Goly layout uses 4 inductors per channel, 22mH, 47mH, 2x 100mH. I guess depending on the switch pos, some inductors were connected in series.
So it is not a 1:1 replacement when using the don-audio or other inductors.
But i am still waiting for the pcb to arrive to confirm my guessing.

See my post above. Don Audio G-Pultec inductor will definitely work, you'll just need to make your own plan for mounting it.

EDIT: I just looked at the Don Audio page and, in addition to having the math for this circuit clearly laid out on the inductor's product page, they even offer a little daughter board for it with mounting holes. So they seem to have thought this through.

 

[eltorro84]

Found this, which suggests to wire the inductor switch AND caps offboard.
Post in thread 'Cinemag CML-150T in Gyraf Pultec ?'
Cinemag CML-150T in Gyraf Pultec ?

Its about about cinemag (i would like to get that one too), but as the don audio also has different inductor valus than goly pcb requires, i suppose the same is neccessary for the don audio inductor. (i am talking about the „g-pultec inductor“)

EDIT:
Had to update to see JMans post, It was initially hidden.
With your explanation, it makes sense. I just have to figure out the right spots on the pcb to inject the don audio inductor outs

 

[eltorro84]

Fortunately there is also a pcb to wire-mount the don inductor

 

[antiehdas]

See my post above. Don Audio G-Pultec inductor will definitely work, you'll just need to make your own plan for mounting it.

EDIT: I just looked at the Don Audio page and, in addition to having the math for this circuit clearly laid out on the inductor's product page, they even offer a little daughter board for it with mounting holes. So they seem to have thought this through.

Ye, sorry for that stupid question, after i wrote my post with this question i found all the info at don audio........

 

[antiehdas]

I used these cheap inductors from Reichelt and they do a good job.

https://www.reichelt.de/stehende-induktivitaet-11p-ferrit-22m-l-11p-22m-p73006.html?&nbc=1https://www.reichelt.de/stehende-induktivitaet-11p-ferrit-47m-l-11p-47m-p73008.html?&nbc=1https://www.reichelt.de/stehende-in...0000-h-5-20-khz-l-11p-100m-p73010.html?&nbc=1

Thanx man ! i will order most of the parts at reichelt, so thats really helpfull !

Some people wrote that suoundwise the don audio inductor would be better. is this some magic stardust, rose-water thing , or is it a diffrence ?

 

[eltorro84]

From what i have read, the inductor is a major part of the pultec sound. But could also be snake oil if you are not using real vintage parts for the whole build.