UTC A-35 tranny for direct box?

Hi all, first post. Did a search here to see if i can use the UTC A-35 tranformer as a direct box but didn't find much. I did find some data sheets and found out it's an transistor interstage tranny. I wired it up like a direct box and plug a bass into it. It seemed to sound ok but just wondering if it's messing with the sound since it's a intertsage and not a input or matching tranny. Thanks in advance.

I would say that it's perfect for bass. 610 dc ohms means mega henries, hopefully.

That's a big core to magnetize, so bass probably will drive it better than guitar at the lower picking pressures. I would expect some high end rolloff with that many turns if used for guitar. I would say the hotter your bass pickups, the better.

Wiread as 10k:125 it should work OK for a direct box... BUT, this is a gapped outpt transformer, that can take 8mA throught the pri winding and still work very well in a 30-20k range, and very high output level. It´s probably not nickel core, most probably no nickel in there. I would use it as a RCA BA2A tube mic pre output or any other schems that asks for a gapped transormer, as it´s a little hard to come by a transformer like this one you have.

I would say get a mic input transformer, nickel core and use it reversed as a direc box transformer... Should give you lower distortion on instrument levels also.

Shoot, Raf, didn't you just send me an A-35? Or was that an A-25?
Sheesh, so many carcasses around here, I can't think for the smell.

Possibly 50/50 Ni, no gap but F type lam I bet.

Yeah, that was an A25. Or was it a A26??? shit! Anyway, you already took it apart, remenber? :twisted:

bout the F lam thingy, should all lams be oriented the same side? Like a gap with no isolating material, that is???

I´ve heard many old gapped units don´t have a isolating material at all in the gap. Simply all lams are oriented to the same side and it´s all that it takes to make most cores good for 5-20mA and lots of level for line outputs, depending on size.

Yeah, thats right.It was an A-25, which, if you look at the cut sheet, is very similar to the A-35. I would say it's the exact same transformer only with a few less turns. So our chit is totally together on this pup.

Did I post the gory details already?

I must have. But what did I call it?

I just found the carcass. Or carcasses. Did you send two?

I am guessing 10 henries on the pri for the A-35, which is less than expected, but with the lams sitting one way, and low NI, less henries so the dc does not twist the core into a contortinated cupie doll. :shock:

OK, Jerry, beginners luck I guess. Here is your transformer, sans a few turns:

http://www.groupdiy.com/index.php?topic=9325&highlight=utc+a25

Raf was right, .002 gap, Kraft Paper.

My guess is that it will make a good DI tranny, but not a great one, due to the core arrangement. You will probably find that you have to hit the strings pretty hard to get enough output from that guy.

If you smack it on the ground real hard, you might get the lams to cut their way thru that paper gap, thus increasing the permeability of the core, and therefore the henries and sensitivity. It's knowing which side to smack that is the tricky part. However, at the same time, the physical shock will re align the iger section molecules so that the Ni lams will turn into M6, so you break even. :razz:

hehe CJ... :thumb:

Yeah, I sent you two UTC A25s. Both were bad thought... It was for a second chance if you couldn´t get it rightr the first time. But it seems that no matter how complex the tranmsformer might be, you always get it in the first time... You are getting better and better in this fine art! I hope you can use the second one for parts, or maybe some other things. You are very creative in alternative transformer uses :grin:

If you smack it on the ground real hard, you might get the lams to cut their way thru that paper gap, thus increasing the permeability of the core, and therefore the henries and sensitivity. It's knowing which side to smack that is the tricky part. However, at the same time, the physical shock will re align the iger section molecules so that the Ni lams will turn into M6, so you break even.

Click to expand...

THat´s Rock´n´Roll
A video of this action would be appreciated verrrrry mucho :green:

Thanks for the info! Picked 2 up at a electronics salvage shop for $10. They have piles of assorted audio trannys, TT patch bays, test gear, and just about anything you can think of.The TT bays sold for $40 each. I think they have a web sight and it's called Skycraft Salvage. Maybe make a "hit list" of items you guys/gals want and next trip up, I'll play runner and mail to you. Thanks again.

Skycraft :green:

You have to type that slowly...with a far-away look in your eyes.

SKYYYYYYYCRAAAAAAAAAFFFFFFT!

If I don't go to heaven, I hope I go to Skycraft. :thumb:
Charlie

I have been going to this place for years! Some of the deals:
Metcal solder station-$75
Weller DS1000 d-soldering station-$175
Hotwezzer- $50
RCA 12AX7 $6
Yamaha PM180 (baby PM1000?) $50, they had 6
Orban 536A d-ess $35, one channel out
Tapco 4400A (cheese reverb) $30
Simpson 260 $25, the OLD type

I built my shop and studio from this place! 3 hour "visits" are the norm for me and the dumpster diving is great.

Is there a website for this place?

If it's still there and not floating around the sky somewhere:

http://www.skycraftsurplus.com/