Bad OT in Crate VC5310

[Suburbanite]

Hi all,
So after a few simple tests I can confirm that somehow my OT has died (Long live the next one) but before doing a straight swap I wanted to explore the possibilities of installing an OT with a 16ohm tap as well as a 8 (its often sat on a cab to raise it off the floor may as well plug it in) would this be possible or would I end up replacing the power transformer and installing a choke??

[NorCalTuna]

OK- those 4 el84s probably want a primary impedance of 4k. I'd recommend this Fender Bandmaster, Pro, Vibrolux, Tremolux Style, 40W Output Transformer 4/8/16 Ohm but you seem to be in london so shipping could be spendy; any bandmaster or ac30 unit will work, just find a roughly 30w ot with 4k primaries. Also, you want to use the 4 ohm tap and the 2 8 ohm loads in parallel, lest the jack, speakers or cable go intermittent.

You'd only have to change the power transformer if you were changing something pretty far out there like tubes ("New Post: I put KT120s in my vc5310!") and chokes are great, but as long as it isn't making more noise than you need or you want it to have different "pick and note feel" like sag or compression, everything should be fine. You're changing the part that needs to be changed! The jacks may need some thinkin' but find an ot and make sure it clears mechanically and you'll be able to bolt it on somehow well first and then hooking it up should be a good project. Btw, Heres the schematic...

http://www.blueguitar.org/new/schem/...ge_club_50.pdf

[Suburbanite]

Thanks for the reply

I swapped out the 3 10's about a year ago for a couple of 12's, and was thinking if changing the OT I could swap the speakers for a couple of lady lucks (16 ohms the pair) that I have then I could have 1 16ohms out and 2 8ohms out ala Orange style if I'm using my 4/12 as well (16ohm)

would a 40watt OT be enough? I thought the crate was a 60watt amp?

RS stock and order Hammond OTs but I've not heard much about them (either good or bad)

http://www.hammondmfg.com/pdf/EDB1760L.pdf

[NorCalTuna]

I think they rated it for 50w. It's even possible it does it! here's a different transformer thats rated a bit more...

Fender Bassman, Super Reverb, Concert Style 50W / 60W Output Transformer 4/8 Ohm

I'm not exactly sure of your needs speaker wise but your 412 could be most likely re-wired to 4 ohm-

[pdf64]

Bluebell are UK and stock Hammond stuff, Philip is a good guy. Yes, the 1760L should fit fit the bill, electrically at least (4k2:4/8/16).
Guitar-trans-output
I've bought a couple from him this year (so far).
Pete.

[Suburbanite]

Many thanks, I've been bashing the net for the last hour trying to find a uk supplier,

[Suburbanite]

I have a Orange Dual Terror and a old intermusik amp that are both 16ohm and a few 16ohm cabs which might explain my fixation on converting to 16ohms, and that crate is proper loud - even louder than my mates Orange ad140 (most of the time I have problems turning it down, even on 1 its too loud for some rehearsals - something I should really look at while its on the bench, and some new caps I guess)

but I digress

[NorCalTuna]

The clean channel vol pot is linear, which is suspect for the volume issue. Changing it to an audio taper or tapering that pot would help that but I don't know how those pots are mounted or how crafty you wanna get.

If you can't find exactally what you're looking for, you could get a matching transformer that lets you hook whatever to whatever- weber has them- so you can hook your 16 ohm cab to your 4 ohm output through the transformer-