Building first Amp, 5E3 clone with a twist.

[ECHAP]

Hey guys - first time poster here. Been reading for a while and really enjoy the site. For a little background, I am a Ham for over 20 years and have been playing with boatanchors for years. I enjoy the electronics part of Ham radio more then the talking part. That said, I have an extensive collection of old transmitters and receivers. All where picked up cheap, broken and ugly. I have restored many and repaired all of them. A few years ago I started playing electric guitar and of course with my long time interest in electronics, and boredom with radio circuits, I started looking at schematics for vintage guitar amps. Going thru my junk, I have found about everything that I needed to build a 5E3 type build. Not being a wood worker, I decided to use an old Solid state amp, a Crate XT65R that was broken and picked up cheap from a friend. I gutted it but decided that I needed new chassis as the old one was just to ugly, and had a few bends that didn't want to play nice with new layout. The transformer that I am planning on using is from an old early 50's Zenith console The part number is 95-921 100 watts. As far as I can tell from the net, it's 340-0-340 @ 95ma, 5V @ 2A , and 6.3V @2.5A, so should be quite adequate for a 5E3 build. I ordered a few parts needed and decided to use new tube sockets as well. Got a 5E3 turret board from Ebay a while back and am just waiting to get the chassis done and the parts I ordered. Hoping to have it completed soon. This is my first attempt to actually build something, I am normally just repairing and replacing what is there, so this is all kinds of fun. I thought about using a kit, but I am to cheap and am only going to have a hundred in this deal.
Here are a few pic's of what I have right now.







Here is a pic of my screen from AutoCAD of the chassis layout. Do you guys think I will have an issue with my layout?

5e3 crate update layout Model (1).pdf




Found a 1960's tube organ on freelist here that uses a pair of El84's, so that might be my next build if I can pick it up today, waiting for email back, so cross your fingers.


eta: took advice below and figured out the pic's. Little different then what I have normally seen, but nice.

[Tom Phillips]

Hello Eric,

Welcome to the forum. I too started with Ham radio many decades ago and enjoyed building equipment more than the radio communications. I changed my emphasis to guitar amps to build equipment for the band and my personal use.

Note that you can upload your related photos directly in your thread hear at MEF. It works great and is easier for everyone to pull up your photo set while they are reading your post. The link to the FAQ page that covers the attachment upload process is at Music Electronics Forum FAQ . This allows one to upload other documents such as acrobat files in addition to photos.

Cheers,
Tom

[mozz]

I was going to say save the tube sockets from the tv, but often they were pretty cheap wafer types. I really hate new sockets, chinese, they don't have the good tolerances old quality sockets have. Get that organ, many good parts including the wire. 340v transformer may be a little high on voltage, use a old 5y3 for a good B+drop. N3UVT here.

[Justin Thomas]

Could use a 5R4, too... Same voltage drop as a 5Y3, but takes higher AC Voltage & Current. Use JJ6V6s til you get the power supply squared away - I wouldn't trust any other new production 6V6s, as your B+ will probably end up around 410V... All my opinion.

Justin

[ECHAP]

I was going to say save the tube sockets from the tv, but often they were pretty cheap wafer types. I really hate new sockets, chinese, they don't have the good tolerances old quality sockets have. Get that organ, many good parts including the wire. 340v transformer may be a little high on voltage, use a old 5y3 for a good B+drop. N3UVT here.

Yeah, the tube sockets are the old wafer type, and pretty ugly looking. I debated it, and figured the chinese crap would be better. I have a bunch of old tubes, so I am not buying any new tubes. I have a few different NOS tubes to try. My 6V6 that I have are all steel instead of glass, so I will be on the prowl for new GT on the 6V6 at hamfests in the future. Maybe a future build will use all vintage parts. I have a few more transformers.

I pulled a bunch of cloth wire out of it, but this one will be all new wire.

Here are the sockets.

[Tom Phillips]

I like to use tube sockets salvaged from old test equipment and surplus military gear. Most of the stuff came from equipment that was given away at the end of hamfests. Stuff that didn't sell and that nobody wanted to haul home. The salvage work takes time but the resulting parts such as real cinch brand tube sockets are worth it to me. Also, it's my contribution to reducing the landfill a bit.

[loudthud]

Be aware that a metal 6V6 or 6L6 uses pin 1 for the metal envelope. Ground pin 1 on the socket, don't use it as a place to solder the other end of a screen resistor or grid stopper.

[Justin Thomas]

One question - that PT. 340x1.4 = ~480, minus 50 for rectifier drop, then what, another 40V for current draw? Still leaves nearly 400V B+ for metal 6V6s. Anybody ever run those like that? Worst part, you can't see the fireworks if there are any, until it's too late... Just curious, vertebrate than sorry...

Justin

[Chuck H]

I'm still abroad and for some reason my circumstances aren't allowing "like"s. So I just want to say... Likes to all. I just love reading the forum and all the responses from guys that have the experience and chops for this work. So I often give "like"s. Right now I'm limited to just nodding and thinking "Yep... Yep... Yep..." So, anyway, A bunch of likes from me. That includes our new guy OP

[ECHAP]

I bought a Tektronics vacuum tube scope a while back to salvage parts from, but then the damn thing worked, so I recapped it and have been using it. It's only 10mhz, so not really that useful, but that early 60's Tek stuff sure was nice. This one is almost mint, so I felt that it deserved to be saved.

[mikepukmel]

Awesome, can't wait to hear a sound clip!