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  1. Spanngitter

    Bringing the 1974x closer to the 1974

    I built a few 18W, normal (Tremolo) ones as well as TMB Version And even 18W 1959SLP. What worked and sounded for me the best is a TMB build with an IGPW Transformer Set, NOS ERO MKTs, CF Resistors and a complete Set of NOS Brimar Valves. It’s followed by my daily practice amp, a build with...
  2. Spanngitter

    Vox AC15 Reverb Issues

    16Vdc is insufficient on Pin 4/8, it will work but have not much headroom...did you count pins correctly? Pin1 is denoted by a dot on the IC and usually a square mark around the contact hole in the PCB. 25Vdc to 27Vdc is what should be measured there against GND, see also the Schematics you...
  3. Spanngitter

    Vox AC15 Reverb Issues

    Pls check FS3 which is a 2R2 fusible Resistor. If this one degrades or blow you lose the +/-27Vdc supplying the OpAmps. Since there is apparently still some operation of the OpAmps it is most likely degraded and Voltages on the OpAmps is insufficient => check on Pin4 resp 8 to GND
  4. Spanngitter

    Need to replace the valves from my JVM 410HJS?

    Nope, for a proper IR it would require a DSP Treatment with the correct Impulse Response. The DI Out on the JVM is a simply R/C Filter cutting down the Frequency to a range between 100Hz and 7kHz supposed to sound like a 4x12 with V30 (which is beside the 20/80 and T75 IMHO one of the worst...
  5. Spanngitter

    Need to replace the valves from my JVM 410HJS?

    First of all, that Amp sounds normal but back up that Gain and Volume a tad.. 2nd the DI output will ALLWAYS give you fuzzy tone if there is no Amp Sim/IR utilized to record as it plainly taps off the Sound after the PreAmp so no Power Amp and Cabinet involved to shape the sound as you expect it..
  6. Spanngitter


    There is multiple Versions of the 2210 out there, they differ in the Diode clipping Stage, in Channel Switching (Transistor vs logic IC) and a few more small points. I had multiple 22xx here for repair and fluppy tone usually denotes the requirement of a Cap Job, checking all the GND connections...
  7. Spanngitter

    Can caps/ resistors become microphonic?

    I had Ceramic Caps going microphonic as well as Sliver Micas, CC Resistors and even (only once so far) an I would not exclude anything, e.g. that grey shielded tubing Marshall used in some JCM800s does also sometimes go microphonic...
  8. Spanngitter


    JVM 410 => 70mA per side ( which will run each tube (if properly matched) at ~35mA). I prefer usage of NOS EL34 I still have for these amps (RFT made RSDs) at 66 (33)mA but also have at least half a dozend 410 equipped with JJ EL34 II and those like to run best around 72-74mA / side. An in...
  9. Spanngitter

    1987x with 3 month old eh 6ca7s bias 10ma apart

    Voltages on Pin 5 identical? You could have a leaky coupling cap to the valve socket where the high bias is noticed...
  10. Spanngitter

    tubes tied ?

    Nope. However, if u ship me the box I will take care to dispose the content properly....
  11. Spanngitter


    JJ 5881 do work but I would also vote for KT66 if you have the Version with the Dagnall TX OP 00003 which runs at 8k primary Impedance, something KT66 do love.
  12. Spanngitter

    Jvm 410c buzz

    I would suspect that your Bias runs away and your tubes do get overloaded, hence the hum... if you know what your do you can quickly check your valves for any signs of red plating or excessive blue haze in the glass envelope or measure Bias (requires opening of amp). If this all sounds like a...
  13. Spanngitter

    Can a blown screen grid resistor cause this?

    Are you sure you have the required expertise to work safely on that amp?
  14. Spanngitter

    JCM800 2204 Gut Shot Questions

    Try to source some green Ero/Roederstein MKT 1822, they fit perfectly. if it would be my amp,and since you have to get in anyway, I would replace all coupling caps with MKT, in my ears they sound perfect in old Marshall’s…
  15. Spanngitter

    Vintage Modern 2266 failure

    I'll recommend that and also to repair both of these joints with led containing solder (allowed for repair). Removing the PCB is most of the work, removing solder and reflowing the least part, maybe this is all included in bench fee if you have a humble tech...
  16. Spanngitter

    Vintage Modern 2266 failure

    It will happen again as I suspect a cold solder joint where the "Pin" of these round connectors is soldered into the PCB. High current and RoHS solder do not comply, so it needs to be reworked. For that the PCB needs to be pulled unless somebody is brave enough and solders the heater wires...
  17. Spanngitter

    Vintage Modern 2266 failure

    Pls check Heater Connections on CON11, depending on quality of solder joints there can be a problem lurking at these connector spades. Also I'll recommend to check if the -15Vdc Voltage Regulator REG1 is still workin properly, I have seen this one fail also in the past.
  18. Spanngitter

    1959HW tube bias problems

    Could be also related to bad/leaking coupling caps from PI (0.1uF =Bass, 0.022 = Lead) to Pin 5 of the Power Tubes....
  19. Spanngitter

    Dc Heater Filaments Through Power Amp?

    Peavey Schematics are as precise as Engl or Mesa Boogie. Parts missing, incorrect part values, failing to follow any common nomenclature in drawing. On above linked Amp Schematic: Heater Supply for V1/V2 seem to come out of nowhere, designated with 6V (6Vdc?) and maybe linked to point 6V1...
  20. Spanngitter

    Dc Heater Filaments Through Power Amp?

    Nice when you call somebody an „expert“ when yourself fail to read schematics correctly. The Preamp Section of the VK has DC Heaters whilst the PI/PowerAmp has DC elevated AC Heating (plus some awkward serial connection of the filaments which turns the Amp dead silent as soon as one Heater fails...

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