External makeup amp for Pultec eq.

[TheGuitarist]

So this might be a crazy idea so please stop me if this is just wrong.

I know people are making solid state amps for pultecs with 2520s etc etc... but could i just simply use a 4 channel preamp with line ins?

Thats what the 1272 was designed to be wasn't it? Just a line amp.

Anyone have any suggestions on which pres i could use/modify to use just line ins. I'd prefer to go with projects that have pcbs available, then i can just make small modifications and still use the preamps. Or if its actually simpler just to make a small makeup gain circuit then i'm sure i could have a go at it. If thats the case, then i'll take a look through the other threads of people who did that.

I'd probably need 4 channels (dual peq1 and dual meq1)

Oh also, i couldnt actually find this, do you lose much of that pultec vibe by using solid state instead of tube? I'm willing to go tube if it sounds better, just a bit scared of the electricity.

So any suggestions would be great.

Also how hard would it be to make one PSU to run all 4 channels... would that just be as simple as having enough VA and then doing some funky connections? (maybe a link out with IEC cables.)

 

[Sleeper]

I think Stefan made one with a Neve amp. Search that.

I did a lot of reading before I started mine - which has a 990 make up stage so it's very close to the API version and it's also not finished yet.
It's important to get the termination of the pultec just right.

You already have the 4 channels?
If you do the build out to absolutely work with your pre's you should be fine. Of course that's the trick isn't it.
If you are building the pre's or don't care about modding what you already have
I would maybe make a special insert point for the pultecs. 
It's closer to a cut and paste this way, and that's faster -for me-
When I cut and paste well ;D, I don't have to spend too much time on the bench, just a quick scope to make sure that theres nothing super freaky and then start using the gear as you make listening tests. ;D

If you are good at math and like to bench test, just do that.

Great luck.
Kelly

 

[mitsos]

If you look at the enhanced pultec, it uses NE5532 for balance/debalance and (I assume) makeup gain. Gustav is doing boards for this and the amp and filter should be available separately when it actually becomes available. I thought it'd be available already but I think there was a mixup in the amount of boards made or something.  That'd probably be easiest, next I'd say the neve output, not a 1272, just the output stage. But then you need an output trafo, no? You could stick any preamp circuit in there. One member recently made a makeup gain amp for a summing bus out of SSL9K pres and re-worked the gain switching so that it was limited to the range most useful to him. There are lots of ways to do it.

 

[syn]

...or look for newyorkdave eq thread and posts by newyorkdave, somewhere he explained how to use mic pre as a passive eq gain makeup.

 

[3nity]

i'm not sure how this will sound in practice but i think of using THAT Debalancer and balancer..
What you guys think?
Thanks.

 

[mitsos]

what about gain?  DOA?

 

[Tubemooley]

Pretty much all of those ideas will work. How they all sound is the question. They will sound good but will they sound good enough? That depends on each guy sitting there listening to these different amplifiers. Not using the stock Pultec tube make-up amp will not destroy the Pultec vibe. It will effect it but it won't destroy it. I have a dual mono Pultec copy I made. And I never could get this buzz or hum out of the amp circuit. But the passive filter section itself works great and definitely does the Pultec thing. So we use make-up gain from a separate box. We have several different choices for that. I'm not sure exactly which one my engineer favors these days. So..... IC opamps will work. DOA's will work. A tube circuit will work. They will all work and work well and sound good. But they will all be slightly different in the end. DW.