Yamaha / Soldano T100 choke mod and tube advice needed.

Discussion in 'Amps and Cabs' started by Smgbad, Jan 29, 2012.

  1. Smgbad

    Smgbad Supporting Member

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    Got the amp yesterday. She sounds great... I'd love to know what the seemingly very popular "Choke Mod" is and how to do it.

    I also just checked out the tubes that came with it and am wondering just how good or bad this tube setup is:

    V1 - Sovtek 12AX7 LPS
    V2 - Sovtek 12AX7 LPS
    V3 - Sovtek 12AX7 LPS
    V4 - Yamaha 12AX7 (original)
    V5 - Sovtek 12AX7 LPS
    V6 - Sovtek 12AX7 LPS
    V7 - Sovtek 12AX7 LPS
    V8 - Mesa 6L6GC
    V9 - Mesa 6L6GC
    V10 - Mesa 6L6GC
    V11 - Mesa 6L6GC

    The amp functions fine, but that seems like a lot of LPS's, or is that normal?

    I just got a Hughes and Kettner Vortex 412 Slant cab to go with it (for the practice space), now I am in search of the best 2x12 cab for my home.
     
  2. zzmoore

    zzmoore Member

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    Ask one of the tube guys, or Mike Soldano himself.
    Looks like V3 and V5 are a Cat Follow.
    The LPS tubes may have a problem with the Cathode Voltage in those slots.
    Best
     
  3. Norjef

    Norjef Member

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    I recommend a mix of TS and JJ preampers to taste - try TS in #1 - then JJs in dirty channel tubes and TS in rest. Try both in PI slot. Years ago I put a set of LordValve Philips 7581s in the power tube section - expensive but lasted YEARS. Recently retubed with JJ 6L6s - sounds about as good as much of OD is preamp based.

    Amp REALLLLY comes alive and fattens up (in dirts) when MV is +6 (loud)
     
  4. Smgbad

    Smgbad Supporting Member

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    I appreciate the help. I'll let ya know how it turns out.

    Any ideas about the choke mod?
     
  5. Smgbad

    Smgbad Supporting Member

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    Ok I found the info here on the choke mod (FINALLY... I thought I'd have better luck finding Jimmy Hoffa at one point in my search). Here's what the guy said:

    " CHOKE MOD INSTRUCTIONS: There is a 470 or 500 ohm 10 watt resistor on the power supply board. Remove the resistor and connect a choke in its place (not the same physical place, it wouldn't fit. Connect the two wires from the choke to the two pads where the resistor was connected) You can use any choke from another 50 or 100 watt tube amp. Our choke is about 3 henries, you need no more than 100 milliamp current capacity. . . . . . I did the choke mod in about 30 minutes. You basically just desolder the 10-watt resistor which looks more like a brick than the conventional 1/2 watt color band resistors you may picture in your head. Anyway it took me a minute to find, but you can look up a picture of a 10-watt resistor if needed. Then you just take your choke/inductor, align it on the chassis over the spot where the 10-watt resistor sat, so that the wires can route almost straight down to be soldered in. Drill a small hole for the two wires to drop through. Then I just used two self-tapping metal screws to connect the choke to the chassis there. Solder up the two wires in the holes left from the resistor (I don't think polarity matters here) and you are done, man! The choke mod is absolutely essential if you want to restore the loss of bass response at higher volumes. In other words, you get the CHUGGA CHUGGA back. Aww yeah! "

    Now I can do this mod myself pretty easily, but what is the Henry value I would want to go with. No clue as I've never dealt with converting over to a choke before.
     
  6. Smgbad

    Smgbad Supporting Member

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    Bump. Still need to know what to look for in a choke as far as henrys
     
  7. Smgbad

    Smgbad Supporting Member

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    For those with T100s or T50's that are curious, just order the 6L6 Filter Choke from Mojotone. It was $17 shipped and is 3.5 Henrys @ 100mA . Just what tech support @ Soldano suggests.
     

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