MXL V67 transformer update

[Flatpicker]

[quote author="craigmorris74"]...PS: Has anybody tried a decent capsule and a decent transformer in this thing? Possibly creating a decent mic for <$400 USD![/quote]Well, there's no such thing as a decent transformer for the stock circuit. You have to redesign the whole circuit to use the correct (much higher ratio) transformer. And I remember Gus doing just that, but don't remember the exact meta thread(s) where it was discussed. So seriously, one needs to scan the entire microphone meta (and not just in the ones that are "MXL? related) because this stuff is scattered all over it.

As for the schematic, I had posted links to it in the previous threads, but since then I had to change my ?flatpicker? email address due to massive spam and lost everything in the process, so the links were dead and I edited my post to delete them. I?ll dig up the schematic and repost a link to it as soon as I get time. (I can?t seem to find it at the moment.)

 

[tommypiper]

There is a transformer Jensen recommended to me as a replacement for the stock transformer in the V67. I sent my V67 to them and they looked at it, tested it. They were very generous, sent me a whole schematic and diagram for no charge. I believe it was the JT-MB-D they recommended. I can't find the hook up details, may have lost it. I bought the transformer, but for other reasons never installed it.

You could give them a call and see what they recommend.

<edit> Found it. It is the JT-MB-DU.

 

[craigmorris74]

Sorry for the rant earlier, by the way. Darn kids really should read the META. Tedious, yes. Informative-heck yes.

 

[Flatpicker]

I found the JT-MB-D, but not the JT-MB-DU. Can you post a link? I'm curious about the specs. Could be a semi-custom that they are not listing on their site.

 

[edanderson]

the U stands for uncased, as in, it is supplied without the mu-metal can so that it will fit inside the shielded compartment of the mic. the price will be a bit lower than the non-U version.

ed

 

[tommypiper]

That's right. Thanks, Ed. U means uncanned. Otherwise it won't fit inside the mic.

If I recall, the hook up was in reverse, as 2:1. So, what's usually the secondary is in series and on the input side, and the output is what's usually the primary, taking just one primary for the output. If memory serves. If i'm not mistaken.

 

[CJ]

Rant no problem. I see your pain. Meta's becoming too large and too numerous = people being overwhelmed.
Heck, I have not even scratched the surface.
I alwyas try to spit out a quick answer if i have one. Otherwise, I am a waste of food and gas.

 

[craigmorris74]

This question reflects my limitations on electronics knowledge, but shouldn't there be a couple of components that you could change to get the circuit to work with a more standard mic transformer?

 

[CJ]

Most U 67's that came out of Gotham had the tube circuit mod for lower impedance and a little less gain.
Triode connection, with the transformer being fed off the cathode resistor, right?

 

[enthalpystudios]

[quote author="Flatpicker"]I?d swap out C2 with a polystyrene, C4 and C8 with a Panasonic HVs, and C6 with the best quality film cap you can fit in there.

Next, order some sample lams from Mag Metals and re-laminate the transformer. The number is:
Part Description: 2425 EE
Grade/Gauge: 8414
Quality: Superperm[/quote]

out of curiosity, just because a lot things have been discussed in the thread, this is for the v67g, right?

And thats using the same bobbin/wire, eh?

thanks, and sorry to resurrect la thread anciento

billy

 

[Flatpicker]

Boy, you sure have to watch what you post around here because it can come back and bite ya. Keep in mind that I have not tried this - I?m only speculating a good starting point. Try high quality WIMA or other brand polypropylenes for C2 as well and see what you like. Also, nowadays I?d try really low ESR electrolytics like Nichicons, or even try low ESR tantalums besides the Panasonics for C4 & C8. (Some surface mount tantalums have really low ESR ? don?t use surface mount electrolytics, though ? they suck!) My advice for C6 still stands, however.

Oh, and yes, it's for the V67.

 

[enthalpystudios]

cool cool, thanks tim......

friend of mine picked one up and asked if i had any ideas for him to mod it... he may not, as for the time being it has turned his behringer pres into the bottleneck.

thanks again though, i'm going to write this down for him

billy