Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: jeff on January 28, 2011, 12:38:25 am

Title: Univox U45-B
Post by: jeff on January 28, 2011, 12:38:25 am: I have a Univox U45-B that my bro gave me with a blown OT. I got this as a replacement https://secure.cedist.com/scripts/foxweb.exe/moreinfo@d:%5Cdfs%5Celevclients%5Ccedist%5CELEVATOR.FXP?item=P-T291
I need a 16K so I figured I'd wire it as a 8K:8 and use a 16ohm speaker

It lists it as a 8W transformer. Is this big enough? How many watts can I expect from 2 6BM8s PP?
Title: Re: Univox U45-B
Post by: PRR on January 28, 2011, 06:17:39 pm: You already got it? Then stick it in. Try it. It will play.

Two ECL82 might be 9W-10W.

0.7 pounds for claimed 8 Watts? Is this thing similar in size to the original? My suspicion is that bass must be flabby. But go ahead and try it.
Title: Re: Univox U45-B
Post by: jeff on January 28, 2011, 07:31:03 pm: Quote from: PRR on January 28, 2011, 06:17:39 pm
Is this thing similar in size to the original?

Just about

Quote from: PRR on January 28, 2011, 06:17:39 pm
You already got it? Then stick it in. Try it. It will play.

What'll happen to the amp if it does blow? I'm worried about destroying other components tubes, PT etc.
Title: Re: Univox U45-B
Post by: PRR on January 28, 2011, 08:18:11 pm: It won't "blow".

It is too small for "full clean bass", but no harm in that.
Title: Re: Univox U45-B
Post by: jeff on January 28, 2011, 09:12:47 pm: Quote from: PRR on January 28, 2011, 08:18:11 pm
It is too small for "full clean bass", but no harm in that.
By small are you refering to phyisical size or rating? Are you saying up to 8W it will be ok but the more you push it the more the bass will suffer? Or will the bass be worse at any level
Title: Re: Univox U45-B
Post by: Tiny_Daddy on January 28, 2011, 09:55:35 pm: Needs a grounded 3-wire cord too. I'm sure you can make a few safety improvements, cut out the "death cap", maybe add some sheet metal, etc.
Title: Re: Univox U45-B
Post by: PRR on January 29, 2011, 09:08:51 pm: You already got it? Then stick it in. Try it.
Title: Re: Univox U45-B
Post by: jeff on February 03, 2011, 05:13:31 pm: The amp also has a broken circuit board so I have to fix that first but when I get that fixed I'll give it a try. Just wondering if I needed to order another transformer when I order parts for it but I'll use this one.

Thanks for all the help.
Jeff
Title: Re: Univox U45-B
Post by: Tiny_Daddy on February 03, 2011, 08:21:23 pm: Broken circuit board may be replaced with a generic turret board plus a bit of layout with pencil & paper.