Pultec Solid State design questions WE 111C?...Noobie here, please be gentle.

[djayvigil]

Hi guys & gals,

Preface:
As the subject title suggests, I am a total noobie to the diy world and much of electronics (in practice).  Learned some theory as I was Electrical Engineering in college for a few years so I'm not a total dummy.  However, that was 10 years ago ;-D  So, please forgive my naive questions.  I have strategically chosen projects that are easy with many parts pre-built which cuts down on the assembly, risk and skill required... Hopefully.  Treat me like a 5 year old because that's pretty much my proficiency level, apologies.

Now to my questions

I've purchased filters/inductors which are pre-built (just need to be wired up) and even pre built gar 2520 op-amps for this Pultec Solid State.  My first question centers around the choice for transformers.  I realize that this has been exhaustively covered in many threads BUT I haven't seen anyone using or even proposing using what I am considering.  The guy who built the filter/inductors had alluded to the possibility in his pdf file.  I have NOS Western Electric 111c's and the originally used Triad HS-56V's.  With the 111c's being 600-600 line transformers...it seems I may have gain loss trying to include these.  I've read so many good things about these transformers & think they sound as though they could be tasty.  Just want to get all possible challenges of this, best approach & specific suggestions on how to alleviate any mismatch here or if it's even worthwhile.  Also, these Pultec's have a high possibility of preceding/succeeding newer gear wanting to "see" different impedance.  I've read resistors can help.  Also, what will be the best way to wire the terminals if it will work etc...

Also, the BOM says to use alpha pots on these... my instinct tells me more like the plastic bourne types or perhaps grayhills.  Your best suggestions for these would be appreciated as well (values etc>>).  I really want everything to be rock solid and sound beyond excellent instead of skimping on components and regretting it later.  However, I'm not intending on putting Elma's in there either.  A little too much for my blood there    So, moderately affordable options with maximum quality & reliability.

Thirdly, I have op-amps with long pins and I think I'll need the mill max sockets but will I need some kind of pcb to wire from there?  See, I told ya I was a noobie  :-[

Thank you in advance for your help...it's greatly appreciated

Btw, are these image verifications impossible or what?!?!?!?!  ??? guess I'll listen instead...sheesh

 

[My3gger]

Hi,

don't worry too much about the parts, this circuit is pretty minimalistic. Capacitors can be polyester or polypropylene like Orange Drops, Xicon, whatever has correct values. I tried polystyrene and couldn't hear difference between them and cheap polyesters in fast test. Counductive plastic potentiometers are nice, although very small and difficult to solder point to point, particularly when you want to attach two ground points on one leg.  Alphas work well, as do Pihers and others, you might try "better" later. Lorlin switches are good too, lots of good gear has them inside.
Looks like you have two nice input transformers, i'm not sure if you can wire them as outputs too. WE 111C doesn't have so much loss that you would have problems with gain. I would try Edcors if you need another one for output, they sound just fine.
Not sure what you mean about those op amp sockets, veroboard is nice for such a simple projects because it allows a lot of experimenting. Just build it as simple as you can and try other parts when is working well. Except for transformer, inductors and chasis, it shouldn't cost more than 100$ per channel, probably less. Wire can be expensive, i bought 16ch Sommer multicore cable with mesh shield. It is easy to work with, has low capacitance, it is cheap because a few meters of 16ch lasts a long time.

Good luck with your build.

 

[ForthMonkey]

Hi,

I'm noobie,too.  ;D  I'm designing solid state gain stage with custom made input transformer and Triad Utrad A-61J.Design same as Lang PEQ-1 gain stage.You can check.I'm waiting for parts.When it's done,how it sounds.If you want,you can try this.

http://groupdiy.com/index.php?topic=58126.0

 

[emrr]

111-C will 'outperform' any of the usual choices, you never see people use them because they are so big.  There's a GS thread from a guy who built some various preamps using 111C's and UTC LS-30's; you add rackspace height using these, definitely luxurious. 

What it 'sounds like' is a different question.  I don't personally like the sound of the stock HS-56 transformers, yet they are the sound of a Pultec in many ways.  They add a certain buttery fizzy whip cream smear that a 111-C or LS-30 will not.  They do 'soften' in an obvious way. 

 

[djayvigil]

Thank you for the swift replies...thought I'd come back in a week with 0 replies still 

Hi,

don't worry too much about the parts, this circuit is pretty minimalistic. Capacitors can be polyester or polypropylene like Orange Drops, Xicon, whatever has correct values. I tried polystyrene and couldn't hear difference between them and cheap polyesters in fast test. Counductive plastic potentiometers are nice, although very small and difficult to solder point to point, particularly when you want to attach two ground points on one leg.  Alphas work well, as do Pihers and others, you might try "better" later. Lorlin switches are good too, lots of good gear has them inside.
Looks like you have two nice input transformers, i'm not sure if you can wire them as outputs too. WE 111C doesn't have so much loss that you would have problems with gain. I would try Edcors if you need another one for output, they sound just fine.
Not sure what you mean about those op amp sockets, veroboard is nice for such a simple projects because it allows a lot of experimenting. Just build it as simple as you can and try other parts when is working well. Except for transformer, inductors and chasis, it shouldn't cost more than 100$ per channel, probably less. Wire can be expensive, i bought 16ch Sommer multicore cable with mesh shield. It is easy to work with, has low capacitance

Thanks for the info here!  I'll look into the Lorlins & Pihers.  My plan was to try the WE111c on input and the Triad HS56v as outputs.  I don't know if I have to configure the triad as step-up or if they can both be line to line 600?  Veroboard...Brilliant!  I was considering the breadboard but that looks to be a better option.  Any type of veroboard better than another for audio circuits?

Hi,

I'm noobie,too.  ;D  I'm designing solid state gain stage with custom made input transformer and Triad Utrad A-61J.Design same as Lang PEQ-1 gain stage.You can check.I'm waiting for parts.When it's done,how it sounds.If you want,you can try this.

http://groupdiy.com/index.php?topic=58126.0

Yeah... I am also planning a little 8 or 16 channel summing box with pan/gain and I want to have a big fat gain stage, possibly WE111c again ( or A20)!  So, I'm into researching all the gain stages I can to find out my best approach there.  I'll take a look!

111-C will 'outperform' any of the usual choices, you never see people use them because they are so big.  There's a GS thread from a guy who built some various preamps using 111C's and UTC LS-30's; you add rackspace height using these, definitely luxurious. 

What it 'sounds like' is a different question.  I don't personally like the sound of the stock HS-56 transformers, yet they are the sound of a Pultec in many ways.  They add a certain buttery fizzy whip cream smear that a 111-C or LS-30 will not.  They do 'soften' in an obvious way. 

The UTC LS is still swishing around my brain too (possibly on that summing box).  I have a bunch of 3U boxes so, I'm thinking big transformers...why not?  8) As far as the HS-56, I wanted to maintain some of that Pultec flava!  I've certainly got the ability to inject the rigid edge to sounds also.  I sort of like the idea of vintage sounds combined with modern sounds.  It seems people are after either one or the other sometimes.  For the music I am putting together, there is great strength in the fusion of digital sharpness and vintage warmth.  Gear seems to be following this same trend recently.  However, I do have some A20's and that had occurred to me as a possibility.  Just worry about the 500 ohm on the back end... I've read that it's not that big of a deal too.

 

[wolcott]

Im taking it that this filter info is from the ebay guy selling complete filter/inductor units .
Im curious as to how good his inductor really is  .
There are some good threads here about solid state builds and my interpretation of them was that the inductor and amp section areas are the main mojo spots ?      1:1 transformers dont really exhibit a ton of character correct ?
So the 2520/filtercaps/and inductor are the places to experiment .methinks

 

[emrr]

Pretty much anyone in an AB test will be able to pick out 111C from HS56 very consistently, not too hard to do with  LS30 and 111C, being more the same class.  Even 1:1, many of these pieces still have an identifiable sound. 

 

[Gold]

not too hard to do with  LS30 and 111C, being more the same class.  Even 1:1, many of these pieces still have an identifiable sound.

I use LS30's as input transformers for the Quad Eight 312S I use in my mastering chain. I have used 111C's as an M/S matrix in the past. I'd say both have a pretty minimal impact on the sound, at least the ways I've used them.  You might like it a little better or a little worse but you won't go "what happened"? IIRC a 111C gets to 0.1%THD @40Hz at +35dBM or something ridiculous like that.

 

[emrr]

Yes, it's minimal but identifiable.  Both less transparent than a high end Jensen 1:1, much more transparent than an hs56.

 

[wolcott]

Please report back on your findings " djayvigil "
Id like to know if that ebay dude dose good work .
Looks like he sticks to one type of capacitor but
Saves winding inductors and sourcing filter caps .  8)

 

[djayvigil]

Wolcott,

Yes, it is indeed the eBay dude.  I'll definitely report back.  It just seemed to be more suitable for my experience level.  May be a little while as I'm still designing/ordering the panels.  Piece by piece I guess...get there eventually .  I'm actually going to open up one of those filters & check out the components soon. It seemed to me he understands inductors &  winding process pretty well & I read positive things.  We shall see!  If it don't pan out, I saw an awesome & intriguing SS build from Radiance on here.  Quite a bit more complex however.

Emrr/Gold

I guess I expected subtle effects on those 111c.  I hear they have slightly better body in the low registers & all around transparent.  Definitely the best balancing performance without question.  So, they ought to clean up any unwanted noise floor for a clean input stage.  The relationship between the inductor, 2520 & triad is indeed where the color will happen.  I kind of like the idea of 1 clean & 1 colored xformer.  Big n bad, so to speak!  I just ordered a NOS Altec 1612b & I hear that's quite a noisy compressor (probably a future project cleaning that one up a bit) so that could be a good combo?.?.
How it's driven going in is likely where I can achieve those subtleties.  This gets to an important point which is the impedance on both sides.  I'm concerned about getting the very best out of these as they play such a big role in several places throughout the production process.  This will be my debut with vintage 600 ohm gear.  Any suggestions on how, specifically, to make it play nice with the modern stuff are certainly welcomed.  Still I've read that it's more in the instance where you have 600 ohm gear back to back...this is where you experience the drops in signal.  Mathematically it seems to be the case.  Peterson over at DIYre had a vid on a variable impedance box for mics that looked ultra simple.  I have no idea if that's appropriate in this case might be ok if you had a high quality detented pot & if you're well educated on you input/output impedances.  Again...don't know...could be complete un-aldulterated newbie foolishness there on my part. Probably better off with some kind of step-up xformer in this case.
I'm getting into tangentville here, sorry ;-)