DIY Pultec EQP-1A Layout and Pics

[dukasound]

Hi Ron
Great, Great, Great
Duka

 

[kent]

Now we know your secret! That first picture gave it all away... you use Elmer's Glue-All instead of solder.

nice,
kent

p.s. turrets rule!

 

[thestudio]

What's the diffrence between a EQP1A and a EQP1A3 ?????? :?:

 

[jrmintz]

[quote author="Viitalahde"][quote author="Fletcher"] the EQP-1A3 is exactly the same unit as the EQP-1A in a two-RU form[/quote]

..Fletcher wrote that here:

http://www.mercenary.com/readguidtovi.html[/quote]

I don't believe that's correct. The filter may be the same, but the amplifier is solid state in an EQP-1A3. I have a pdf of a Pultec brochure that says that. I don't have it with me, though.

 

[thestudio]

Is threre a shematic around on the meq5 with the API 2520 amp? :?:


Also, has anyone emailed "elco" the person with the pultec style knobs? Everything was set to purchase two sets of knobs through PayPal but now his emails have stopped and his phone is disconnected? :?: :?: :?:

 

[tony dB]

cool pics
just one other fine project done to an absolute PRO level, as already many times here :shock: :shock: :shock:

Fine work! me jealous :wink:


Cheers,

Tony

 

[thestudio]

Can someone tell me the skirt OD" of the Dakaware knobs used for the Pultec eq...... :roll: Found knobs but there's a coulpe different sizes......

 

[CJ]

darn! i have some at home.
from memory i remember them almost being equal to the height of a 1u box, which would put them at 1.75 inches at best? probably closer to 1.625.

i will measure tonite.

 

[thestudio]

Thanks for replying ............ :grin:

I believe one of the knob measurements is 1 9/16? and the skirt is 2", which might be what you have at your house but please check.......thanks again :grin:

 

[bblackwood]

[quote author="Viitalahde"][quote author="jrmintz"]I don't believe that's correct. The filter may be the same, but the amplifier is solid state in an EQP-1A3. I have a pdf of a Pultec brochure that says that. I don't have it with me, though.[/quote]

Hm, checked it out myself and you're correct. 1A3 is 2u and has op-amp makeup gain.[/quote]
Actually, I think it was made both ways - tube or 2520 makup gain...

 

[thestudio]

Brad, that is correct.........


cjenrick,

I found some other size knobs from Dakaware which the skirt goes up to 4".....Wow!!! I need to know the correct size.... is 2" to big or to small :?:

 

[cayocosta]

I believe the knobs I used were 1.5" skirt.

 

[jrmintz]

On Jakob's site in the DIY section about pultecs there's a pdf brochure entitled: 'Purple Audio's original schematic for the amplifier section'. I don't know how to link it from here. Page 2 describes the EQP-1A3 as a solid state pultec with a passive filter and an operational amplifier as opposed to the EQP-1A which is described as a passive filter with a push-pull amplifier. I've been told that the EQP-1A3 had an API 325 card as the amplifier. Does anyone know if that's accurate, or did they just use a 2520 or something similar?

Thanks[/url]

 

[cayocosta]

Here are NOS 1.5" skirt knobs from the source I used:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4673&item=5717067470&rd=1

 

[CJ]

1.5 is correct!
get brass inserts if you can.
cj

 

[dukasound]

Hi
I cant find place 10K resistor on Gyraf pcb.

Can anyone help me with inductors?
Thanks
Duka

 

[mesmer]

What inductor was used in the original pultec? how does the cinemag compare in sound?
Peter

 

[CJ]

Somebody mentioned Torwico in another thread, but then that got disputed and I do not know where we stand. I have had two sources tell me it is wound on a one inch outside diameter torroid.
Probably lots of turns as the A numbers were pretty low back then.
Just call up Fair-Rite and tell them you own a cellular network and will need 5000 torroids a week for your transmitter filters.
Then they will deliver stuff like this for free. Half will be broken, but hey, the price is right. Then the trick is to get the rep to quit calling you every day!


cj

Then, get an old IC tube and chop it, or use a popcycle stick and wind your heart out:

 

[mesmer]

Now thats diy!
How did you know I owned a cellular network?
Peter

 

[thestudio]

I also would like to know the difference on the cinemag and Torwico Pultec? There's a big difference in size :shock: