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jross68052

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About jross68052

  • Birthday 01/19/2022

Converted

  • occupation
    Guitarist
  • hobbies
    Music
  • Location
    New Jersey
  1. Myles, I checked my bias currents on my 1996 Fender Prosonic. I measured 60ma in class A, 34 ma. in class AB, and 30 ma with the soldid state rectifier. The amp is supposed to be 30 watts class A, 50 Watts class A/B and 60 watts with the SS rectifier. Any idea why the bias current would drop with the SS rectifer? I sounds best in A/B. It breakes up too early in Class A. Your response is always appreciated. Joe
  2. Myles, I was reading an interview with Bruce Zinky who was the designer of the Fender Prosonic. In the article he states" See those ceramic disc caps on the tube sockets ... Cut them out.. Apparently these can cause a massive local feedback. Can you help me understand what he is talking about? What are these parts,and where are they located? I would like to fund them and remove them if this will be an improvement. Thanks, Joe
  3. Myles, Quick question. I ususally run my Prosonic amp with the Class A rectifier setting. My understanding is that in Class A it creates 30 Watts. This gives me a good usable amount of power for club gigs. My question is: Do I need a balanced phase inverter tube for this mode of operation? Thanks, Joe
  4. I explain this in depth on my GAB website. Thanks for the advice. In installed a balanced JJ phase inverter tube before my gigs this weekend. The Marshall TSl tone and power were right on. Joe
  5. Myles, Heres my question of the week. If you have a typical push pull amp and the phase inverter tube happens to be not balanced as it should, What would the amp sound like when it is turned up? Would this produce a non harmonic distortion? The reason I ask is that my Marshall TSL60 sounds great at low volumes and the preamp out to a PA with digital effects sounds really great. But when I turn the amp up a bit, the power amp distortion sounds real nasty and not even musical in my opinion. I have ordered a balanced phase inverter tube for the amp. Do you think this may improve the problem? Or am I on the wrong track? Thanks, Joe
  6. Myles, I meant mv in the last comment not ma. Thanks, Joe
  7. Myles, I have a Marshall TSL60 that seems to be out of spec. The manufactures recommends setting the bias voltage to 80ma as measured by each side of a three pin connector on the back of the amp chassis. When I turn the bias pot all the way up I only get 70 ma. The pre-amp sounds good, but when I turn the amp up the sound in best described as harsh, brittle and cold. I think the power section is under biased. I have tried three sets of new power tubes so far with no improvement. Any suggestions for fixing this problem? Do I need to replace or upgrade the output transformers? Your advice is greatly appreciated. Thanks, Joe
  8. Myles, Heres my question on the week. On a Fender Prosonic, what pre-amp tubes are used for the clean channel and which are used for the drive channel? Or are all used for both? Thanks, Joe myspace.com/hotmonkeymusic
  9. Myles, I read your piece about removing two tubes. I will ax that idea. How about using four THD Yellow Jackets in a Marshall 100 Watt JCM800? Any experience with this? Thanks again, Joe
  10. Hey Myles, My question of the week. Can I remove two power tubes from my 100 Watt Marshall JCM800 and get the eqivalent of a 50 Watt JCM800? Will this damage the amp? Thanks, Joe
  11. Myles, I have installed a new pair of JJ's 6L6 in my ten year old Fender Prosonic. They sound incredible in the calss A mode. My Bias probe says 70 ma. in this mode. Is this too hot? Thanks, Joe
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