Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Toxophilite on October 30, 2014, 12:12:22 am

Title: revibe question
Post by: Toxophilite on October 30, 2014, 12:12:22 am

Can I build a 6V6 revibe using a transformer set(PT and OT) from a single ended El84/6BQ5 amp? (an old grundig reel to reel)
or do I need specific 6V6 transformers (I'm pretty sure it's mostly the OT that might be specific)


THanks

Title: Re: revibe question
Post by: DummyLoad on October 30, 2014, 03:45:37 am

Quote from: Toxophilite on October 30, 2014, 12:12:22 am

Can I build a 6V6 revibe using a transformer set(PT and OT) from a single ended El84/6BQ5 amp? (an old grundig reel to reel)
or do I need specific 6V6 transformers (I'm pretty sure it's mostly the OT that might be specific)


THanks

yes. it will likely work. what's the B+ of the grundig? 


--pete

Title: Re: Revibe EL 84 transformer set Question
Post by: Toxophilite on November 21, 2014, 10:37:24 am

Sorry for the delay
Other projects intervened
I get around 260 vdc at the EL84 and around 270 closer to the PT..I did this quickly this morn so I haven't found where the rectifier is hiding yet


THanks

Title: Re: revibe question
Post by: DummyLoad on November 21, 2014, 10:48:21 am

if grundig OT was used to drive an 8ohm load, it'll work.


--pete

Title: Re: revibe question
Post by: Toxophilite on November 22, 2014, 04:59:24 pm

Oh heck 4 ohms
Can I use a different tank, something with a 4ohm load?

Title: Re: revibe question
Post by: sluckey on November 22, 2014, 07:47:09 pm

The OT that Hoffman sells for the Revibe has a 4Ω secondary. So does the OT I used on my Revibe. A 4Ω OT works very well with an 8Ω tank. Besides, you may not find a 4Ω tank.

Title: Re: revibe question
Post by: PRR on November 22, 2014, 09:07:45 pm

It's a teeny reverb tank, not a speaker into a 750 seat club.

4, 8, 16, whatever... just do it. The difference in "power" (milliWatts) is unimportant.

The "problem" is in mixing 8 (4, 16) drivers and tanks with 600 Ohm drivers and tanks. That's enough mis-match to cut the spring drive way off.

Title: Re: revibe question
Post by: Toxophilite on November 23, 2014, 02:30:16 pm

Excellent
THanks very much!
Time to start pulling apart the grundig