Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

my homebrew stereo tube hifi amp photos
#1

I recently built a custom stereo tube hifi amp as a project. My wife added some photos of this custom amp at photobucket if anyone wishes to see them. Its a great sounding amp indeed!Still not completely finished, just working-out the final bugs. The old RCA chassis is a circa 1947 vintage auditorium PA chassis.Perhaps Doug H. can help verify the exact age? This amp yielded me some very expensive highly sought after Western Elec 618 B m.c. input transformers. The chassis had been stored for many yrs with lots of other vintage tube gear I recently acquired. It was in bad shape,some rust, most orig paint missing, ...nasty! It has a perforated metal roll-over wire tubecage not shown in the photos. I stripped all the orig parts & wiring, took the chassis apart, used a handgrinder with wire-wheel brush to take all the old rust / leftover paint off. I repainted it as close to orig colors as possible using automotive lacquers. All the knobs are orig.
I then started a complete rebuild as a home hifi stereo tube amp project. Two amps all in one chassis sharing one power supply. I mounted good used tube sockets in the already-punched chassis. I had to cut another hole for the second audio trans.
Built with all used spare parts:
Power trans: good tested used 450-0-450 off mid 50s large (4) 6L6 PA amp,
Matching early 60s Sherwood Labs handwound linear types audio-trans off a previously-hacked Sherwood mod S-5000.

Things I added in the new amp build was DC filament supply to the preamp tubes which allows for a totally hum-free amp design. I thought up the tube layout, and created my own schematic along the way, trial & error. I made some mistakes, found them, and kept moving on, using all parts here in my workshop backstock bins.

The design is simple. Both separate amps are cathode-biased, and tubes can vary , and sub easily. Ive tested the amps swapping in/out EL34s, 6550s, & 6L6s so far. My favorites are the sound quality of the 6550s overall, but all the tubes sound sweet in this amp! The preamp tubes lineup in each individual amp are 6C5, 6J5, w/ 6SL7 phase-inverter, driving either 2 EL34, or 6L6, or 6550s in p.p.Its been a fun project indeed! I have a very-slight distortion prob Im working out, but overall this amp ROCKS the house!

heres a photolink with slideshow if anyone would like to see my new all point-to-point handbuilt amp now in my collection. It was fun adding new-life & reason for future-use to the old RCA pa chassis indeed! ol Tx. Icon_wink

http://s576.photobucket.com/albums/ss202.../?newest=1



Messages In This Thread
my homebrew stereo tube hifi amp photos - by Texasrocker - 08-24-2009, 02:41 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
HiFi (Chifi) tube amp build - but my own design.
It's the other forum. I'm also in DIY, but mostly read there. Honestly, I kinda jumped into this without much thought to...TV MAN — 10:43 AM
Philco 71 Code 125
Hello,  I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated.dconant — 07:57 AM
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM
54C Complete Teardown/Rebuild
Hello roy, here is a link to the schematic . Sincerely Richardradiorich — 11:54 PM
54C Complete Teardown/Rebuild
Richard, The Silvertone 2014 also is a transformerless set, so I am incorporating a 1:1 600 ohm audio isolation transfo...glyphmon — 11:37 PM
Preliminary work on wife's Silvertone 2014
Did an alignment today which was interesting.  IF alignment went great, almost all was already spot-on.  Adjusting on th...glyphmon — 11:35 PM
54C Complete Teardown/Rebuild
The main problem with adding a Bluetooth input is that this set lacks a traditional power transformer to isolate it from...radiorich — 11:19 PM
54C Cabinet Refinish
I started stripping this cabinet before it got super chilly out because I knew I wasn't going to be able to work on ...glyphmon — 11:18 PM

[-]
Who's Online
There are currently 3037 online users. [Complete List]
» 1 Member(s) | 3036 Guest(s)
Avatar

>