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  1. Ronno25

    Is 120vac too close to output transformer a problem?

    I'm working on a new p2p build in a very small chassis. My 120v AC power transformer primary line is going to have to run quite close to my output transformer. Is this going to be a problem for noise, etc? I've never had to deal with this consideration before. TIA.
  2. Ronno25

    Extra eyes on 18w lite layout diagram plz.

    I'm planning an 18w lite build. I'll be using a chassis that already has PT and OPT , a few tube sockets, and appropriate place for a cap can. So my layout has been influenced by this. I'd sure appreciate some extra eyes on the layout. I'm mostly concerned about avoiding noise issues from lead...
  3. Ronno25

    What is considered the quintessential 18w lite iib ??

    Is there/does anyone have a schematic for what would be considered the quintessential lite iib build? I've poked around on Google and found one by a Mark Huss but would like some opinions on what would be considered the standard 18w build. I can't figure out where to find schematics on...
  4. Ronno25

    5u4 vs GZ34 B+ in Princeton Reverb clone

    I've been using an old RCA 5u4 in my princeton reverb clone with a B+ of 390 and ~70% plate dissipation. Curious to find out what the amp would sound like with the called for B+ of about ~420 I swapped in an old Sylvania "big bottle" USA GZ34. The part I don't understand is why my B+ and bias...
  5. Ronno25

    Dimensions JBL D120f

    Does anyone have, or could measure, the EXACT dimensions of a JBL D120f? I don't need the depth, just the diameter of the frame. I'm looking to buy one for a cab that has limited space and wanting to make sure I have enough room before I purchase. TIA!
  6. Ronno25

    Wiring DPDT switch for internal channel jumper

    I just wired up a two channel, two input amp with a channel jumping dpdt switch. The switch works as it should when I have a guitar plugged in. When channel jumping is engaged and nothing is plugged in to the amp there is a loud buzz/hum. I'm using switchcraft shorting jacks. Did I wire this up...
  7. Ronno25

    Replacing switch broke my MXR carbon copy. Troubleshoot.

    When opening up the case of my MXR carbon copy the stomp switch fell apart. I replaced it but now the pedal does not pass signal. Well, actually you still can hear the "pop" being delayed when either the battery or input is plugged in with the pedal turned ON. There is no signal with switch in...
  8. Ronno25

    Output Transformer Ratio & Wiring

    I have an Output Transformer here that has two secondary taps: Both appear to have the same winding ratio. From either green or yellow to black I'm getting a 55.5/1 winding ratio; the same on both taps. From yellow to green I'm getting a 26.3/1 winding ratio. The 55.5/1 ratio leaves me at...
  9. Ronno25

    6g15 noise :(

    I built a 6g15 Reverb Unit clone. Sounds great. But... There is a fair amount of noise (see video: ) especially when the guitar amp it is plugged into is loud or cranked (which is how I run them usually) and the reverb unit is turned up a fair amount. I typically wouldn't run the reverb unit...
  10. Ronno25

    Space between resistors and other components to reduce heat?

    When building amps or doing repair work is space required between resistors and other components (capacitors) to keep them from taking on too much heat? I know it is advised to keep the cathode bias resistor away from it's complimentary electrolytic cap. I see with vintage fenders that...
  11. Ronno25

    Brown Princeton vs Tweed Harvard

    Is there anyone out there who owns a vintage example of each of these? I'd really appreciate a description of the difference in sound. I understand the technical differences (higher B+ in Brown Princeton, 12ax7 vs 6at6 preamp, tremolo in Brown Princeton, etc). I've read through many threads...
  12. Ronno25

    Tweed Harvard with 2x6" speakers? Yay or nay?

    Howdy. I have a Tweed Harvard Clone that I built into a head a cab. I got to thinking I would throw in a pair of 8" speakers for use when I don't have an external cab around to plug into. I now realize the head cab I built is too small to accommodate 8" speakers because it's short by about half...
  13. Ronno25

    Princeton Reverb Build - Troubleshoot

    Just built this Princeton Reverb clone. PT is Classictone OPT - is 1960 Schumacher. Reverb Driver is Hammond Rectifier 5u4 Reverb works. Trem works. Amp makes sound. Sound is distorted. One power tube has almost no current and the other has about 50ma (using current limiter). Power tubes...
  14. Ronno25

    1993 Tele with neck Humbucker. What model is this?

    I found a USA tele with neck humbucker for sale that I'm interested in. I can't for the life of me figure out what model this is. Does anyone have info about this guitar? Value? Types of body wood used? The seller says the pickups are stock. Does anyone have experience with these guitars? Body...
  15. Ronno25

    Vintage Gibson ga-77 amp

    Recently picked this up and am wanting to fix it up and get it running. Anyone have a nice schematic for this thing? What's going on with the tolex and grill cloth? I can't find any Gibson amps online that look like this one. It appears to have the tolex riveted and nailed on in some sections...
  16. Ronno25

    Tweed Harvard 5f10 Bias

    Hi all - I've successfully built a few amps at this point - 5E3, 5F1, VoxAC15 - but never a fixed bias amp until I just built this Harvard 5F10. I used an old 1959 Schumacher Output Transformer, and an unlabeled but used Power Transformer. Specs on the PT are about 278-0-278 HT. Current...
  17. Ronno25


  18. Ronno25


  19. Ronno25

    1964 Franken-Bassman. What is going on here?

    I picked this up knowing it had some modifications. I ended up more surprised than I ever expected. I'm confused as to what I'm dealing with here. Initially, I expected to find a non-original power transformer and an added rectifier. What I found was a non original power transformer, non...
  20. Ronno25

    RG174 shielded cable - Where can I use it safely in the circuit?

    I understand it is safe to use RG174 at the signal input to the grid of the preamp tube. I also want to use it from the plate of the preamp tube to the grid of the phase inverter. Given that RG174 is 26awg stranded wire I'm not sure what level of current it can handle. Where is it safe to use...
  21. Ronno25

    AC15 lite - parasitic oscillation? Funky (bad) noise problems

    Please help me identify and fix some noise issues I'm having with my AC15 build. Thank you in advance!! I built an ac15 lite modeled after a build by Sluckey. I used the transformers and chassis from an AO-39 Hammond. The amp is wired point to point. Tube Compliment: 5Y3, 2x EL84's, 12AX7, and...
  22. Ronno25

    50's Power Transformer for Tweed Champ, 18w Marshall, or Deluxe?

    I'm looking into this power transformer that I got out of a 1950's Capehart-Farnsworth radio / record player. I was initially considering it for a tweed champ or 18w Marshall build but am now thinking of trying the power transformer in my tweed deluxe clone (it fits the cutout in the chassis...
  23. Ronno25

    Potentiometer with on/off switch for NFB loop

    I want to add an option for NFB in my 5f1 tweed champ. I considered a simple on/off switch. I also considered a simple pot. Now I'm considering a pot with an on/off. I want to be able to cut the NFB completely (i.e. none of it in the signal) and I also want to be able to turn it on and dial it...
  24. Ronno25

    lowering 5f1 voltages

    I just built a 5f1 from some organ transformers. It sounds pretty cool. The voltages are high when compared to expected voltages for a 5f1. I used a 340-0-340 power transformer so this isn't a surprise. I understand there are two methods most people use for lowering voltages: Zener diodes or a...
  25. Ronno25

    DIY 5f1 Champ. Scavenged transformers.

    Howdy folks - I'm a relative newcomer to the forum and certainly a newcomer to electronics and tube amps. I recently put together a 5e3 kit to great results. I couldn't have done it without many of your help. You guys know who you are. Thank you. I had so much fun with the 5e3 that I've decided...