Does anyone know of any shootouts using one of these mics? Next best would be some sound clips or album references. Thanks

So in conclusion (or so), HUGE thanks to LDT2 and everyone for these mods. I have 1 request, though: Would it please be possible for someone to post a pic of the 460 taken apart with the mods shown? I've got the schematics of the mods and the factory schems, too. Actual pictures would also be awesome (pretty pictures help people like me understand). Thanks.

Hey Lucio,

I read over your schematics again. Just wondering if you could clarify something.

With the 499K resistors at R3 and R4 are you getting 64V's to the capsule? (w/ the 1050 w/ R5 still in place)

This seems correct. I ordered another capsule from Peluso yesterday, and he said 60 to 64V is about what you want.

As for the tube, I wonder if it might be nice to up the voltage a little bit by playing with R1 and R2?

I guess this was Lucios question also, but does anybody know the ideal voltage that a 12ay7 wants to see? Also, how much that different R1 and R2 values are going to effect the rest of the circuit?

12AX,AY,AT,7 tubes max out at about 300v. As you go up in voltage you do gain more headroom for the mic, but as you go higher in voltage you get a sort of colder sort of sound,sort of less tubey in a sense. You should be able to go up to 200v and still sound good IMO.

mamm7215,

Glad it helped. I hear ya about the pics. I don't have a way to take photos, but I'm sure we can help talk you through any particular part of this. I'll see if I can find a pre existing web photo maybe to use if that would help.

quote:

Originally posted by honkyjonk:
Hey Lucio,

I read over your schematics again. Just wondering if you could clarify something.

With the 499K resistors at R3 and R4 are you getting 64V's to the capsule? (w/ the 1050 w/ R5 still in place)

This seems correct. I ordered another capsule from Peluso yesterday, and he said 60 to 64V is about what you want.

As for the tube, I wonder if it might be nice to up the voltage a little bit by playing with R1 and R2?

I guess this was Lucios question also, but does anybody know the ideal voltage that a 12ay7 wants to see? Also, how much that different R1 and R2 values are going to effect the rest of the circuit?

honkyjonk,

Because I removed C3 the meter only reads voltage before R5. With C3 in place I still had 64v before R10 (as in the Apex schematic). So I would assume, yes 64v is getting to the capsule. I placed the voltages on the schematic at the points I placed the meter probes.

As for R1 and R2, they change alot depending on the values.
For example, when I removed R1 from the 1050 with the cathode follower, the tube voltage raised to 100v at pin 1 and the the cathode voltage at pin 3 doubled to 4v.

When I tried a 390k cap at R2 with the Apex (the 1959 C12 schematic used a 400k here, the 1960 used a 100k) the tube voltage dropped to 54v at pin one.

For reference, the 1960 C12 is marked 66v to 68v at pin 1 with 120v coming in at B+ and 55v at the capsule before the R10 position.

I will say that I initially did the Dave Thomas mods of removing the cathode caps, C6 and C7 and while it did achieve a similar end result sound wise, overall more open with less bass fullness like a C12 is often described, my main problem was the massive loss of gain, especially bad when I then tried the zener change. I had to really crank my preamps to get enough gain back. Noot acceptable to me. Changing the resistors and caps to more closely match the C12 circuit gave me much more openness and clarity while maintaining the gain. WOW is all I can say about the difference.

Now trying to emulate the U47 is another story. I still tried to replicate the circuit as much as possible, but because of the tube differences, etc I just had to experiment a bit more. I mentioned that in the original post. The U47 only had 34v going to the tube, but it's a different animal. I will say that if you leave the original 270k's at R3 and R4 it is less open sounding or less highs, whichever, but the voltage to the capsule will raise to around 78v and consequently this adds harshness to the sound. Thus, I stuck with the 499ks.

I don't know if I mentioned this earlier, but the difference between using a 12Ay7 or 12AT7 in the 1050 is very noticeable. The AY7 is clearer and has a more extended bass response, where the AT7 is thicker and warmer with more lower mid fullness and color. You really have two different mics depending on which tube you use.


MPCNYC,

Good info to know, thanks.


This tube thing is so cool.

Lucio

Another question...Is it now the thought with the 460 to NOT remove C9 and C10? Just replace with .001uf caps?

Hmmm....I would say remove them, especially if you are replacing the transformer for anything half decent. Where'd you here about keeping them?

Doesn't seem to make too much sense to me.

Michael

http://homerecording.com/bbs/showthread.php?t=196274&hi...ght=apex+460&page=14
This is the last thread of a related post at homerecording.com C9 and C10 are RF filter caps, the stock 0.1uf is said to be too much but 0.001 is better without having to remove them. Just asking...

It will help RF, better than no caps there. But, the mic will sound better without them. Again, with a decent transformer that shouldn't be in issue. I've removed those caps entirely on about 6 mics I've mod'ed and have yet to have any problems in a very RF rich environment like New York City.

I say don't use anything there and if you have an RF problem you add the caps at that point and you could even just wire up a cap in the mic cable it self...which would also potentially effect the sound in a potentially deliterious way as well. There's an interesting thread on RF on Klaus Heyne (did I spell his name right?) mic forum

K, no caps it is. Thanks.

Yeh, I thought about this for a bit and haven't had any problems with RF either, so I'm just leaving them off. It would be a drag to replace them at this point 'cuz I've already removed the wires too.

I will say that if you're after the U47 thick and warm sound or something darker, leaving the stock caps at C9 and C10 in does help roll off the ultra highs, but if you want open transients take 'em out for sure.

Lucio

Just out of curiosity...has anyone tried modding/reworking the PS beyond the aforementioned Zener swap(s)?? It looks relatively simple on the inside...but than again, my DIY-ing "Horns" are still kinda green

Again, I have to stress many thanks to the likes of MPCNYC and LDT2, as well as everybody else on this thread for your much valued insight!


P.S.--anyone hear that Black Gate is Nomore...kinda sad.

...funny that you mention the ps overhaul. I've been mentioning that I've been trying to do one with the assistance of a friend of mine. But, sad to say the thing is sort of DOA right now....I've got to figure out what is wrong with the thing...I'll keep you all posted.

SubvertRecordings,

Thanks for the heads up on Black Gate. That's a drag. I guess we'll have to stack up while supplies last.

Has anyone found another brand that even comes close?

Bummer.

Lucio

Yeah, the only reason I ask about the PS (besides the fact that it seems kinda simple inside that box)is because the mains tranny in there is pretty shoddy looking

I think that the power supply can be improved a bit. My experience tells (I've had some nice power supplies built for some other mics I have) me that it can make a subtle but marked difference. The main thing I've heard with power supply upgrades are a little bit more openness in the high end, and perhaps in the sound in general, and a nice supply can the mic a little bit quieter.

Overall I think the experiments that guys are doing are yielding changes in sound that are much more apreciable.

I don't know if you all had heard this before, but in an early post by Dave Thomas in at GS, he mentioned that, if you leave the cathode follower in the mic, that it would be possible to remove the tranny from the mic and upgrade the tranny in the PS to something larger like the CM-2461 or the St. Ives tranny from a Neve 1073.

Just thought I'd add that fuel to the fire.

I'm pretty sure that's not what Dave Thomas meant. The 2461 transformer is a mic transformer not a power transformer. The power supply has a power transfomer. You could change the power tranformer but I'm not sure that would make a huge difference.

Perhaps the confusion arose because Dave did mention that you could put the Cinemag 2461 in the power supply box, instead of in the mic, as a 2461 won't fit in a 1050 (without a bit of dremmeling of metal) or a 460 in their stock form. You would be limited to a cable of about 6ft, or you would get signal loss. So, you wouldn't upgrade or change the power transformer...you'd just put the mic transformer in the box so you would have mill the mic.

I've put 2461 in 1050's with cathode follower and it sounds really nice, a sort of bigger sound than the 2480.

Here's a link to the post, it's #66.

He specifically says, "The output impedance is low enough that you could remove the transformer in the 460 and put a larger output transformer in the power supply. The St Ives 6.8k to 200 ohm transformer in the Neve 1073 comes to mind or the Cinemag CM-2461."

I'm sure that you're right, but it sure sounds like that's what he's saying.

Lucio

And that's what I'm saying : )

You don't remove the transformer in the power supply, it is not the same type of transformer, it's a power transformer.

I talked to him about this back in the day. He IS referring to using a larger mic output transformer which doesn't (at least not easily)
fit in the mic body but will fit in the ps box. Again you can do this but, because the mic's output transformer is no longer in the mic and in the ps box you will have to use a short cable from the mic to the ps box where the transformer resides, as low as the impedence is it still can't really drive a long cable run.

So, it ends up being a mod not to the powersupply but to the mic.