Warm Audio WA412 Mod

[BerndVP]

Hi,

I have an Warm Audio WA-412 and think about changing the:
Input transfo, Output transfo and DOA to CAPI ones.

What are the things I need to be checking before changing those components?

 

[TillM]

I would first change the DOAs and check if it makes a difference.
I think the altran xfr make a good job.
Sure the Capi transformer are top notch, but before you spend a lot of money for new ones, I would first try the DOAs.

I don’t know the circuit from the warm audio, but by changing the input Trafos you maybe need a new Zobel network.
Also the pinout from the transformers could be a bit different to the Capi ones.

 

[BerndVP]

Hi,

Thanks for the reply!
I ordered new DOA first then.

I see they’re using JH capacitors.
Was maybe thinking swapping them out for Nichicon.
https://www.jianghaius.com/PDF/CD263-1.pdf

What do you recommand?

 

[TillM]

Why want you change them ?
It makes no sense in my opinion.

 

[samguaiana]

Genuinely curious if this unit needs mods except for the op amps. Anyone have some insight?

 

[McIrish]

I know this is an old thread. I just bought a Warm WA-412. I'm not sure what everyone thinks they will gain by replacing the DOA and transformers. It seems to do the API kind of thing fine as is.

 

[3nity]

Don't those pres use Cinemag transformers? If so no reason to replace them.

 

[Mikeyrad]

Any update to modding this unit? I have one and thinking about modding it

 

[amplexus]

Any update to modding this unit? I have one and thinking about modding it

If they’re using Cinemag transformers (which are gonna be pretty accurate given that Cinemag was Richenbach that made the originals for the 312 predecessors at MAP/Melcor)- then I can’t think of anything in particular to mod other than rolling some various flavours of 2520.

The 312 is about the simplest preamp design to clone- input trafo, op amp, output trafo. There arent even any coupling caps in the signal path.

I might argue for using higher reliability caps on the power rails, maybe a styrene feedback cap, better gain switch unless they’re already using something of quality like a greyhill… but those would all be reliability and longevity things- basically zero impact on tone.

There’s really not a ton to mod in the basic 312 circuit that isn’t the op amp, assuming quality trafos have been used.

 

[Mikeyrad]

If they’re using Cinemag transformers (which are gonna be pretty accurate given that Cinemag was Richenbach that made the originals for the 312 predecessors at MAP/Melcor)- then I can’t think of anything in particular to mod other than rolling some various flavours of 2520.

The 312 is about the simplest preamp design to clone- input trafo, op amp, output trafo. There arent even any coupling caps in the signal path.

I might argue for using higher reliability caps on the power rails, maybe a styrene feedback cap, better gain switch unless they’re already using something of quality like a greyhill… but those would all be reliability and longevity things- basically zero impact on tone.

There’s really not a ton to mod in the basic 312 circuit that isn’t the op amp, assuming quality trafos have been used.

I saw revive audio has a mod for $450 for everything i believe. That seems reasonable because after you buy the unit and have it modded you are saving a bunch of money and have damn near the real deal unit.

 

[grid_stopper]

I saw revive audio has a mod for $450 for everything i believe. That seems reasonable because after you buy the unit and have it modded you are saving a bunch of money and have damn near the real deal unit.

it looks like the revive mod doesnt touch the input/output transformers(which arent cinemag, fwiw-they are altran's). it seems like you are paying for an upgraded psu, a recap and a new DOA. doesnt seem like its worth an additional 450 to me, but YMMV

 

[dmp]

Why mod it? If it were cheaper I'd understand but it's not a cheap preamp. A lot of 312 clones have been built with Altran wound transformers. I thought the CAPI EA2622 was wound by Altran in fact. And I've never heard a big difference in DOAs. Putting a Jensen JT-110k-HPC in place of the Altran on the input is the place I'd expect possible (slight) improvement.
Is the noise floor high? Otherwise why do anything to the PSU?
Does it do a good job recording tracks? If you do a 10-20 track recording does the mix lack clarity and depth?

 

[Toobme]

I tracked drums with that pre for a couple months, then sold it to buy the guts for a 412 clone using Capi i/o and tried various 2520's from him as well (built quite a few during the pandemic).

The warm is fine, just fine. But I prefer the sound of my Capi pres.
What I preferred in the Capi's that I found slightly lacking in the Warm was a bit of clarity or edge (on stereo overheads) and an insane bottom end from my kick-in mic.

I do tend to agree, though, not much benefit in modding that circuit. Nothing that Capi hasn't already done/considered. Build a new one and then go crazy with all the fancy caps and 1% resistors!