• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

1954 Regency HF-150 Amp???

I was looking for a good DIY amp project to get into tube amplifiers and found a 1954 Regency HF-150 on ebay. I figured that the bid price at the time was a good deal for the transformers alone so I placed my rock-bottom bid and actually won it. I've been scouring the internet for information about the amp but have come up empty handed. Has anyone heard of it? I've found lots of sites for amp refinishing with some really good tips but I need some specific schematics for this model. I'd appreciate some tips on where to look. Thanks in advance!

josh
 

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Thanks!

I'm ordering that 1954 review that you mentioned ASAP; it seems like a good place to start. As for the schematics, the search will continue (sigh). I guess I don't really need them since I can just replace like for like as I go-- it's not as if there will be much left of the original when I'm done, save the sockets, transformers, and chassis. There's just something a little daunting about starting a trip without a map. I guess I'll just make the map as I go. I've been taking a crash course in tube circuit design as well; it seems as much art as science. Thanks again!
 
Alright- The amp finally arrived and it seems to be in good shape. The Sam's photofact is in the mail. I'm getting new can-caps from VibroWorld; they're hard to find! They're 20/20/[email protected], [email protected] and I'm really not skilled enough to make my own. Being born in 1971, this is the first thing I've ever worked on without a PCB...

From the beginner's stuff I've read on designing tubes, I can understand most of the circuit and I'm working on my own schematic. What is the rationale for the 3 different pre-amp tubes? (see picture)
 

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pjdaoust

Member
2010-04-19 1:03 pm
Regency HF-150 ... stories

Alright- The amp finally arrived and it seems to be in good shape. The Sam's photofact is in the mail. I'm getting new can-caps from VibroWorld; they're hard to find! They're 20/20/[email protected], [email protected] and I'm really not skilled enough to make my own. Being born in 1971, this is the first thing I've ever worked on without a PCB...

From the beginner's stuff I've read on designing tubes, I can understand most of the circuit and I'm working on my own schematic. What is the rationale for the 3 different pre-amp tubes? (see picture)

Great to see a young-timer taking an interest in these oldies. The 3 pre-amp sections are one for the phono preamp which, incidently, has several equalization modes. This amp was made right at the time when RIAA recording Equalization was standardized in 1954. Prior to that time, there were several recording eq's used AES, NARTB etc. The Wiki-pedia has some good history discussion about this.

The second tube has to do with the loudness circuit and the third 9 pin tube is a phase splitter for the push-pull output circuit. The grids for the push-pull outputs must be fed out of phase to each other and the phase splitter accomplishes this task.

BTW, where did you find this thing and how much did you have to pay for it ? I'd love to fine one myself to add to my collection. I mentioned in a previous post that I had one of these when I was in HS and college. I went to tech school for electronics from 1966-68 and at that time they were still teaching both vacuum tube theory as well as the new-fangled transistor solid state theory, as they called it.

There was a GE TV factory still in operation in nearby Syracuse where they were building hybrid tube-transistor TV's. I was fascinated by the assembly line to see how it worked. It was mostly women soldering the chassis and hooking up the PC boards to the main chassis then testing it step by step as it went down the line. This was back in the day when in America we actually made things. Those were the days.

BTW, you mentioned 1971, that was the year I got married. I still have that wife :) and 6 grand children. PJD
 

pjdaoust

Member
2010-04-19 1:03 pm