|Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum|
Please consider donating to help us continue to serve you.
Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
||Thread Tools||Search this Thread|
|8th February 2012, 02:56 AM||#1|
Join Date: Nov 2009
I have been a member for awhile now. Iíve not posted much I mostly read and gain info from the other post. I have decide to do my first real tube project. I have recapped radios, amps and the such. I replace the caps and other parts with the same parts and donít change much. I do understand some about tube theory and ohms law but have lots to learn. So the project I choose to learn on is an amp out of a 1958 Philco console. I want to use it to play my guitar through and a line input for CD, MP3 player etc.. Its tube compliment is a 12AX7 AF amp, 6C4 Phase inverter, 2 6CZ5 output configured in a push pull arrangement and 5Y3GT for a rectifier. I have included a schematic from a Sams photofact for reference (if any needs a higher resolution copy let me know). The second schematic is what I have done to the amp already. I replaced all the electrolytic capacitors and C17 & C18 the filter caps. I cleaned the pots and tube sockets and tube pins. I also removed the multi-gang switch that selected the input and added a 2A fuse. I have measured the voltages they all read about 12% low, which is within spec but I would like to get them tighter. I put a 1Khz square wave through. Distorts on the leading edge, not sure what that means though. I will post photos when I get batteries for my camera. Here is where I ask for opinions and help on what next. Let first state what I would like to do and some questions.
1. I would like to add a standby switch. Where should I put it?
2. Add line input and convert it from stereo to mono. Do I just combine the two signals after they come in?
3. Should I replace all the components with better tolerances?
4. Should I replace the tube sockets and potentiometers with better quality ones?
5. What can I experiment with to change the tone quality?
6. Any other suggestions and opinions.
These should get me started. I will post photos of the amp and o-scope waveforms when I can. I want to go on the cheap however I am open to all suggestions. To my surprise the speakers that got with it sound good. I am going to try and use them. My primary goals are learning more about tube amps and have some fun with it. And hopefully have something to brag about when Iím done.
|Thread Tools||Search this Thread|
|Thread||Thread Starter||Forum||Replies||Last Post|
|Cap Problem with philco 49-1401||gto127||Tubes / Valves||16||11th June 2011 03:40 AM|
|1946 philco amp, tuner, record player||tryonziess||Tubes / Valves||2||26th May 2010 02:29 AM|
|Interesting old Philco electrostatic tweeter||peace brainerd||Multi-Way||0||8th March 2010 11:56 PM|
|1946 Philco Tube Receiver||tryonziess||Tubes / Valves||18||1st February 2010 12:54 PM|
|Bose 1801||jazzclic||Everything Else||0||27th March 2003 05:32 AM|
|New To Site?||Need Help?|