Best API Build?

[rmccam]

Hi Everyone,

I'm well on my way into my current 1290 project so I'm looking forward to what's next. I was thinking of doing 4 or 8 API 312 pres. I was just wondering what everyone's opinion was on which route to go for the most authentic API sound?

Starting with the project itself, I know there's the API 312 Hybrid by Bicycle Recordings, but there's also the Reliquia build from BR Audio, the Eisen Audio DIY500... I know there are a ton of others as well... Better ones? Opinions? Differences?

Okay, how about the op amp? Cinemag? John Hardy? The BR Audio? Others?

Finally, best choice for transformers? 

Thanks Everyone!!

 

[okgb]

The pcb less so than the xfmrs & opamps
there's a thread on BM for Ed anderson's
xfmrs which the cloest thing to Authentic api
the opamp you can change & experiment if you use sockets

So i'd say most api will be parts closest to if not authentic ,
that seems obvious no ?

sorry i see the thread title said best , that's a little harder to define
dependant on the indiviual , of course
but there allot of good parts that you can't go wrong with ,
[ most of them here ] check the meta's & threads

 

[MikoKensington]

I agree with Greg.  The sound is in the transformers and opamp.  The PCB really boils down to your space constraints. 

Obviously, the API 2503/Profile 4804 is the real deal.  Ed's version looks pretty promising. But at the moment the Cinemag seems to be the output of choice. 

For input,  who wouldn't love an AP2622?  There are plenty of choices out there, and I don't there's a wrong one here.  Why is authentic important anyway?  The original might sound like crap on a source, where a cheap OEP might sound amazing.  But, if you're patient, Ed might have something for us here too.  In the meantime, Altran, OEP, and Cinemag offer the most cost-effective choices.

Opamps.  I don't have anything to say here.  I use original Melcor/MAP 1731's or NY API 2520's in all my API style preamps.  I couldn't tell you what anyone's remake sounds like.  Though, I'll be ordering some from Gil.  So, down the road I can offer more.

 

[rascalseven]

I've built many API 312 clones from various bits:  conversions from real API 325 cards (that's how I got my eight) and also from scratch using transformers and doa's from old yamaha consoles and also using Fabio's 2520's with Cinemag 75101 inputs and CMOQ-2S outputs.  I also used to own a pair of Brent Averill 312's that had real 2520's, but Reichenbach iron.

All of them sound good... very pro, very toneful, usable stuff.  Don't get too uptight about the 'authentic' tone, b/c API has changed not only the 2520 over the years, but also the 2503 output trafo.  I believe it was originally quadfilar wound, but in the 90's they went with the litz winding (Profile 4804), which was a departure.  I believe the reason for doing this is that API (Paul Wolfe) felt it was more accurate to the tone of the older API stuff when used with the newer, surface mount 2520 that they were using (and still are, I believe).

Bottom line -- there isn't AN  authentic API sound.  There have been many authentic API sounds, and you can get there with the info and items offered on this forum.

I think most of the 2520 stuff offered by guys who frequent here will do you quite nicely coupled with the iron available here as well (Sowter, Cinemag, Ed's, etc.).  BTW, I'm told the Sowter API input is fantastic.  A buddy, whose ears I trust, told me it's the best input he's used so far (and he had previoiusly used the same inputs I have on mine).

Keep your design near this ballpark and you'll dig the results. 

JC

 

[rmccam]

Thanks for the replies everyone!

I totally understand the authentic argument. Perhaps my wording was a bit off... I've used the Brent Averill 312's, and I've used API 512's, and I like how they sound (even if they are different from each other). Getting in that ballpark is my goal.

So now it's just figuring out what PCB to go with. Any preferences? Does anyone have any opinions on whether or not to go lunch box style?

Thanks again.

 

[peterc]

Rmccam

I have just laid out a new 500 series version of this, & the transformers & opamp combo I ended up with is an OEP 262A3 input, Melcor opamp & Jensen JE123s on the output. The 2520 was a little too muddy with the OEP, but the final combination had a really nice back-of-the-throat silkiness to it.

I just tried it on voice, so I need to try it on some loud sources like drums, but I really like this one (but I already said that....)

Pics to follow soon.

Peter

 

[mitsos]

Just to add... I've used Altran 3402 and Cinemag 75101 trafos... I prefer the Altran on input so far, didn't hear much difference between the outputs.

Qustions for JC... what is the difference between quadfilar (or bifilar, trifilar, whatever) and Litz wire wound trafos? Isn't Litz wire used to make quad, tri, bi, whatever-filar trafos?

 

[rascalseven]

Quadfilar means four equal pieces of wire that are wound, together at the same time, around the bobbin (as opposed to winding one wire, then another, then another, then another in layers). 

Litz winding is taking those same four wires and first twisting them to form a strand or cord, and then winding that cord around the bobbin.

Make sense?  Quadfilar doesn't twist the wires, Litz does.

FWIW trifilar is same as quadfilar just with three wires, bifilar two wires, etc.  Litz doesn't refer to the number of wires, just the fact that they are twisted into a cord first and then wound around the bobbin.

JC

 

[barney]

I've built a set of four using JLM baby animal boards, fabio 2520, Cinemag CMMI-8PCA and CMOQ-2S.  Have been happy with them, sound great.

 

[rmccam]

Thank you all. I like getting feedback on which combinations of op amps and transformers people were happy with.

I appreciate the feedback!

Ryan

 

[3nity]

the best sounding 312 style i pu was using a OEP input/melcor 1731 and FAbio output transformer!!
Amazing.

 

[monkeyxx]

I'm kind of a nut about this topic...sort of.  I really like the API preamp circuit.

My first was the 3124+, with whatever those transformers were (I think a Cinemag of some sort on the input, and a chinese OT).  I didn't prefer the modern API 2520 and when I put in the GAR2520 this became my favorite sound "ever."  Anyway, I really liked this combination.

The GAR2520 is by far my favorite 2520.  In the CAPI VP26, however, I sort of preferred the ML2520 with that circuit.  It was a little leaner and brighter, I think, I found that circuit a bit dark and compressed sounding with other op amps and didn't prefer it to the 312 circuit.  I didn't get a chance to try the Red Dot but I've heard those are great in the VP26.

I've also used the CAPI VP312 a lot, with the EA2622 and the 2503 combination.  I love the GAR2520 in there, too.  I'm thinking about doing a test with the GAR1731 though.  That op amp has some nice "color" to it.  The slightly bright high end of the VP312 stock transformers might be suited to the slightly warmed over Melcor sound.

Lastly, I've made a custom unit using the Cinemag CMMI-8PCA input with the EA 2503 output, and the GAR2520.  This one's close to the 3124+ sound, but the 2503 I think gives it a certain character, a little lighter low end and a slight bit of extra harmonics and color or whatever.

That graph someone posted I think shows that indeed the EA2622 has a little more treble going on than one of the Cinemags.  I hear it that way, too.

I do like all of these preamps, and they all do a fairly similar thing, and are all generally useful, but slightly different sounding.  It's fun messing with different configurations.  I plan to build a few channels with CMMI-10PCA and CMOQ-2 L or S to try that combination.  I'm also interested in the VP28 from CAPI (two op amps and two output transformers!).

I will also say you can get some subtle differences out of the different ways of setting up the circuit, like putting a large electrolytic cap between the 2520 and output transformer to block DC offset (when using the 312 DI circuit).  I actually like what this cap adds to the sound.  As well as probably the VP26 differences compared to the VP312, but I haven't experimented much with those.