Purpleharmonix,

Thanks for the note. I thought I'd read a much earlier posting during my build about the 6-way tone switch that was questionable; your posting was far more recent. Sorry, didn't mean to imply that yours was incorrect.    You're right — my switch goes from fat to thin as I go clockwise. (I noticed that my BadCat's clean channel 5-way tone switch goes from "thin" to "fat" as it rotates clockwise; just as the Matchless manual indicates for the C-30. All in the family, hehh...)

I've got to say the PPIMV works very well. I used it for about a week by itself before installing the VVR. I really like using both the master and the VVR together; I set the master at 9-12 o'clock and use the VVR to knock the overall level down to where I need it. Using just the VVR gets me too much output stage saturation; at least with the stock OT. It just doesn't sound sweet and smooth to my ear. I'd recommend that you try to have both installed. There's really no penalty involved; my VVR rear mount is easy enough to get to. I tend to set it once and leave it, and the MV gets to stay on the front panel.

Also, by using the VVR control at only 0-80% range along with the MV, I avoid the scratchy pot syndrome. I've not bothered to install the 1 meg resistor(s) and caps that Dave Hall recommends to avoid this problem because I don't suffer it in my application. If I had to choose just one option at this point I think I'd go with the PPIMV. Unless you're turning it down ridiculously low, the tone really stays there.

I too have had no luck contacting TDS. Their phone number is disconnected, and I got no response to messages left on their web site. I gave up and ordered a WestLabs OT. Will report on the differences, if any. I really have no particular complaint about the stock OT; it's really pretty sweet on the clean and overdriven channels. Maybe I notice some small non-linear artifacts when I really drive the output stage hard using the VVR. I'm mostly just curious about any possible differences . . . . (A $180 worth of curious!  )

Glad you're digging your amp — wait till you do those PPIMV/VVR mods; there's even more fun to be had!

psamm

I just completed my DZ30 build and thought I'd share a few notes:

1) The 1/4" Cliff jack's washers were too thick to permit inserted 1/4" cables to fully engage the tip once they're mounted on the chassis. If you insert a cable into the unmounted jacks, you can clearly see how the cable tip should be firmly captured by the jack. Using only one of the washers and mounting the jack through the chassis and front (or rear) aluminum faceplates, the Cliff jacks won't be able to completely snag the tip of the connector. Use no washers, and the Cliff jack can't be tightened all the way down. I had to Dremel sand the washers to a little less than 1mm thickness for the jacks to work properly when mounted on the chassis. I used one modified washer per jack, and they now capture a 1/4" plug properly. (The Cliff jacks will work with no modification to the washers, but I prefer to have inserted cables fit fully snug into the jacks.)

2) The 6-way tone switch wiring was a bit confusing; an earlier forum post incorrectly ID'd the sequence. By comparing Nik's circuit board to the "real" schematic, I wired the switch with this sequence: L, K, J, I, N, M — it works as expected. Nik's layout shows the front panel switch wired this way, but if you're only looking at the circuit board, you may get thrown off track.

3) I installed the Hall Amplification VVR board on the back of the chassis between the fuse and the speaker phase switch. This lets me keep the PPIMV master volume functional, and it locates the VVR board right where all the necessary connections are. I took the "Y" connection (as designated on the layout) from pin 8 of the rectifier as my B+ input to the VVR board and sent the B+ output of the board to the standby switch "Y" connection. This way I didn't have to unsolder the output transformer primary center tap or choke connections. See my attached pictures — there's even an existing chassis hole for mounting the MOSFET, and the star ground connections are also conveniently located for the VVR board's ground wiring.

4) The supplied indicator lamp socket was dodgy; the lamp was very difficult to remove and insert. Radio Shack had a nice substitute for a couple of bucks; they also had replacement #47 lamps. The stock red jewel lens fit the Radio Shack lamp assembly perfectly.

5) I'm using Nik's stock transformers for this amp, and so far I'm impressed with the amp's tone — I may try a TDS output transformer just for kicks. If so, I'll do a shootout with clips to see how the two OT's compare.

All in all, this is a killer amp. I also have a BadCat Hot Cat 30R, an Overtone HRM, and a 1975 Marshall JMP Mark II Lead 50w Master Volume — this amp is a fantastic addition to the stable! Highly recommended.

psamm

I too just completed my build and I used the actual "Muchle$$" schematic to make certain the tone switch was wired properly. I wired the switch as L, K, J, I, N, M.

If you look at the cap values, this moves you sequentially from high capacitance to low capacitance. The layout diagram shows this sequence properly on the front panel 6-way selector switch...but if you're only looking at the circuit board, you can get confused by the apparent logical sequence of the letters.

psamm