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  1. maxxi

    JVM410H crunch channel vs 410HJS crunch channel

    Ok, seems the afd mod is worth a try. What voltage/wattage should the cap and resistor be rated at?
  2. maxxi

    JVM410H crunch channel vs 410HJS crunch channel

    Thank you for the info! Really appreciatie it! I did read about the AFD mod, but was thinking if it would be possible to limit it to the crunch channel, as the od channels have a huge amount of gain. Are we talking a huge amount of extra gain on the od channels, or rather a difference thats's...
  3. maxxi

    JVM410H crunch channel vs 410HJS crunch channel

    Hi everyone I have a question that I have been asking myself for a couple of years. What's the difference between the crunch channel of the original JVM and the Satriani JVM schematic wise, and what would be needed to bring the OG JVM's crunch channel up to those specs? I have done the...
  4. maxxi

    Who Designed the JVM 410 Mods on this Forum? Electronics Engineers? Professional Amp Builders?

    I believe Santiago provided the details for that mod back in the day. So I'd say it's pretty legit.
  5. maxxi

    Peavey 6505+ power tube problem

    Got the resistor and bias probe in today. I settled on a bias of 28mV, which corresponds to +- 54V measured on the amps bias test points (before the change in resistor this would only go up to 58, so you can imagine how cold those tubes were biassed). The first thing i noticed is that the amp...
  6. maxxi

    Peavey 6505+ power tube problem

    I checked the bias current at the amps test points for now. Peavey recommend -55v, but the lowest I can get the tubes is -58v, this is by turning the pot all the way anti-clockwise. I ordered a bias probe and a 6.8K 1/2W resistor in case the bias voltage is too low when measured with the bias...
  7. maxxi

    Peavey 6505+ power tube problem

    Update: Soldered in the 470Ohm resistors, reassembled the amp and fitted a matched quad of Sovtek 6l6wxt+'s. Amp fired up as normal, all tubes are getting current now. The amp actually sounds more punchy now 😊
  8. maxxi

    Peavey 6505+ power tube problem

    I've been somewhat naughty and took the power tube board out myself. Went quite well to desolder the screen grid resistors. I ordered some 1K 10W resistors, but those are way too big to fit on that board. Ordered some 470 Ohm 5W ones, hopefully they'll arrive quickly 😋
  9. maxxi

    Peavey 6505+ power tube problem

    I just got around to measure the screen grid resistors, and one is indeed not measuring anything. I also took a look at the plastic connector between the power tube board and the main board, and no burn marks are to be seen. Don't know if it will ever burn seeing the amp is going since 2007...
  10. maxxi

    Peavey 6505+ power tube problem

    OK. Do you know if there are other things I might have a look at while the amp is being worked on? Because I don't really get a high quality feeling from this amp 🧐
  11. maxxi

    Peavey 6505+ power tube problem

    Thanks for the answer. Did you replace it with the stock value, or did you change it to a higher one?
  12. maxxi

    Peavey 6505+ power tube problem

    Hi everyone i recently purchased a used 2007 Peavey 6505+ head. It still had the original Ruby tubes in it (A new set of Sovtek 6l6WXT+ are on their way). When taking the chassis out of the headshell for cleaning i decided to fire it up to check what the power tubes were doing. There i found...
  13. maxxi

    SC20H limited edition

    so, the limited edition is actually cheaper than the regular SC20H? 😅
  14. maxxi

    Mod JVM or sell it?

    I eventually got the JVM modded by my regular tech (40 years worth of experience, and well known around here), and I thought why not write a follow up on the results. You never know it can help someone else on the fence of modding their JVM. What got modded: - R58 changed from 82K to 176K (2203...
  15. maxxi

    Mod JVM or sell it?

    The more I think about it, the more I'm tempted to add a choke as well while the amp is at my tech (the board has to be taken out anyway to do the NFB mod). Any suggestions concerning choke value and Ma's/max voltage ratings?
  16. maxxi

    Mod JVM or sell it?

    Allright, i'm pretty much settled on the NFB mod. The only question is what value to take. I'm considering either 136k (evh) or 176k (2203). 🤔
  17. maxxi

    Mod JVM or sell it?

    If i understand correctly, the NFB gives the amp a more 'raw' type of distortion, rather than a looser feel in the bottom end? Could well be the thing i'm aiming for... 🤔 it's just hard to explain Sometimes what sound you have in your head 😅
  18. maxxi

    Mod JVM or sell it?

    is 176K (jcm800 value) that loose? I would prefer not to drill into the chassis to mount an extra pot, so i would simply ask my tech to replace the resistor. Thus getting the value right the first time is quite necessary 😅 Also, the tone from the video posted earlier is the ballpark tone I'm...
  19. maxxi

    Mod JVM or sell it?

    If I had to guess, I'd say part 1 is the 2203. Part 1 is also the sound i prefer out of the two, but only slight. If part 2 was indeed the JVM, it seems like it would be better to get it modded. Do you remember what mods had been done at the time of recording this?
  20. maxxi

    Mod JVM or sell it?

    Btw, does anyone have some sound clips of their modded JVM? I'm interested in the NFB and anti compression mods to let the amp breathe a bit more

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