Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: vampwizzard on August 15, 2020, 12:55:20 pm

Title: Small PP amp build
Post by: vampwizzard on August 15, 2020, 12:55:20 pm: Hey folks. Was interested in Tubenit's soldano 3-5 watt PP amp and got the iron.. a Basler BE class 2 PT of unknown power rating. Its 400V no center tap, 6.3V@4A and theres a 28VCT secondary that baffles me. OT is a 15W Hammond.

So, SS rect for sure due to a lack of center tap. Is there any use for that 28V winding? I also made the mistake of gigging that single channel ab763 (socially distanced and whatnot) and now wonder if the PT will handle an AB763 with reverb no trem or a D style.. with the 12AU7 output section from something like a Robrob mini. The heater circuit would be good to go. I can hit Basler up on Monday to get full specs for the high voltage winding mA capacity. Are there any schems floating around for that?
Title: Re: Small PP amp build
Post by: PRR on August 15, 2020, 01:14:11 pm: 400V AC rectified wants to be 560V DC. That may not be what you want.
Title: Re: Small PP amp build
Post by: vampwizzard on August 15, 2020, 01:33:02 pm: :l2: glad that it was not very expensive. Minor oversight huh? Got it on the chance it did have a center tap and they mis-listed it.
Title: Re: Small PP amp build
Post by: sluckey on August 15, 2020, 02:32:52 pm: You could do a choke input filter and get the B+ down to about 360VDC.
Title: Re: Small PP amp build
Post by: vampwizzard on August 15, 2020, 02:38:28 pm: I feel id have to dump so much voltage to get it into a territory for a 12A_7 based output from its original state that Id rather just use a proper transformer. That is an interesting, relevant bit of advice though. Thanks Sluckey.
Title: Re: Small PP amp build
Post by: tubenit on August 16, 2020, 05:15:21 am: Quote
Tubenit's soldano 3-5 watt PP

Not sure what this is referring to? Can you provide a link. I haven't built anything like that.

With respect, Tubenit
Title: Re: Small PP amp build
Post by: vampwizzard on August 16, 2020, 07:06:10 am: Quote from: tubenit on August 16, 2020, 05:15:21 am
Quote
Tubenit's soldano 3-5 watt PP

Not sure what this is referring to? Can you provide a link. I haven't built anything like that.

With respect, Tubenit

Probably a case of mnemonics gone wrong on my part. SoLow. https://el34world.com/Forum/index.php?topic=13438.msg127145 (https://el34world.com/Forum/index.php?topic=13438.msg127145)
Title: Re: Small PP amp build
Post by: DummyLoad on August 19, 2020, 03:34:19 am: Quote from: vampwizzard on August 16, 2020, 07:06:10 am
Quote from: tubenit on August 16, 2020, 05:15:21 am
Quote
Tubenit's soldano 3-5 watt PP

Not sure what this is referring to? Can you provide a link. I haven't built anything like that.

With respect, Tubenit

Probably a case of mnemonics gone wrong on my part. SoLow. https://el34world.com/Forum/index.php?topic=13438.msg127145 (https://el34world.com/Forum/index.php?topic=13438.msg127145)

perhaps confused about the author? TIMBO built a low-watt P-P version of the SLO. search for that?

--pete
Title: Re: Small PP amp build
Post by: DummyLoad on August 19, 2020, 03:39:20 am: Quote from: vampwizzard on August 16, 2020, 07:06:10 am
Quote from: tubenit on August 16, 2020, 05:15:21 am
Quote
Tubenit's soldano 3-5 watt PP

Not sure what this is referring to? Can you provide a link. I haven't built anything like that.

With respect, Tubenit

Probably a case of mnemonics gone wrong on my part. SoLow. https://el34world.com/Forum/index.php?topic=13438.msg127145 (https://el34world.com/Forum/index.php?topic=13438.msg127145)

https://el34world.com/Forum/index.php?topic=24604.0 (https://el34world.com/Forum/index.php?topic=24604.0)

--pete
Title: Re: Small PP amp build
Post by: vampwizzard on August 19, 2020, 05:12:13 am: Well.. that’s not the one I was thinking of but that’s exactly what I described! :laugh: That’s awesome!