Well, I'll address the important question first. It sounds very very nice. It far exceeded my expectations. I was expecting the OT to be the weak point but to my surprise the amp sounds very warm and full. The reverb goes from subtle to silly and is quite nice sounding. I was thinking I might want to upgrade the pan to an accutronics unit, but the Belton that came with the kit works quite well. It doesn't have the "sproingy" feel that some spring reverbs have. The vibrato (tremolo) works quite well also. The base tone is very much like a Trinity Deluxe I built last year.
And yes - it is a LOT of wiring! I would not recommend this kit for a novice builder. There's a LOT happening in there. I do have to tidy things up with some zip ties but I think I've gotten it pretty clean considering. You can't really see it in the pic but on the tube sockets I've gone "3D" with the lead dress. I also wired the filaments "Hiwatt style". I never like the elevated heater wiring in old Fenders. Makes it awkward to work in there. There are no noise issues doing it the way I did regardless as all the signal wires are well away from the filaments & B+.
I did upgrade/change a few things along with the signal caps. Here's a list...
- upgraded pots to Alpha standard & CTS
- removed switch on intensity pot (original DR didn't have it. Gives a bit of a gain boost but I didn't need that in this amp)
- upgraded lamp assembly (the one that came with the kit had a cheap feel to it)
- replaced fuse holder (same reason)
- removed ground switch (it was unused anyway) & moved bias pot to that hole for convenient access
- added bias test points to rear panel
- used different ground scheme from original DR & Weber layouts. Have separate pre-amp & HV gounds at opposite ends of chassis (quieter operation)
- "isolated" footswitch and reverb jacks from chassis (lower noise)
- changed reverb pot to audio taper (better control)
- upgraded output tube screen resistors to 1K5W (DR's tend to smoke the stock 470-ohms 2w when tubes fail)
- used GZ34 rectifier instead of Weber "copper cap" (for authenticity only...want it to run stupid hot like the original!
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- aux AC socket is not wired in
I think's that's everything that I changed. Now, a few notes about assembly...
- This kit doesn't have the "refinement" of more expensive offerings (Mojo, Metroamp, Trinity). It took some massaging to get things to line up the way I wanted. Some of the holes don't quite line up as expected. Had to do a bit of drilling.
- second mounting hole for OT was not drilled, but I think that's intentional so you can experiment with placement for lowest interference from the PT. I found it worked just fine mounted in the traditional parallel (but oopposite "axis") position
- Due to the same chassis being used for many of their AB763 based kits, there are a LOT of holes in the chassis to accomodate slightly different configurations. It was a bit disorienting at first, especially considering there's no documentation explaining what mounts where. But after installing some of the obvious stuff it became more clear. I've looked at half a dozen 6A20 build pics and they all mount the OT & choke a little differently. I just went with what made sense to me and the result speaks for itself.
- I'm not a big fan of the "snap-in" IEC & aux AC sockets that came with the kit, but they'll be fine for my application (basement hack kind of thing). If I were gonna gig the amp I'd replace the IEC with a more solid bolt-in type.
- the layout made some of the connections a little challenging and the wiring is tough to keep tidy, but it's a dead-on match to the original Fender layout.
- I would prefer an Accutronics reverb pan, but the MIC Belton unit sounds very good. No reason to change it at the moment
- I would prefer 1/4 jacks for the footswitches, and I considered changing it. Actually, a single stereo jack would have been even better. The RCA's will do until I lose the footswitch & want to use one of the others I have kicking around.
- The chassis have a grounding bolt welded in byut I didn't use it. I couldn't get a tight ground as it started to strip, and it wasn't all that tight. I was using a slightly different ground scheme anyway so no big deal.
And I think that covers all the changes.
The PT provided by Weber has two sets of HV secondaries. I was going to use the higher voltage pair as it appeared from documentation that it would more closely match with the original DR's B+ at approx 415v. People had been getting around 420-440 with the higher voltage pair so I decided to try them. It appears Weber has updated this transformer as I was getting B+ around 500v. That's WAY too hot for most 6V6's and would probably have stressed the rest of the amp too so I decided to use the lower voltage taps. It turns out that these worked out to about 405v, probably due to my slightly higher than normal line voltage, so it worked out prefectly. Again, a little surprising as most people were reporting 385v or so.
I think that covers everything. I have a set of top-hat style knobs that came with the kit, but I've decided to go with a retro-brown look. I've ordered a set of "vintage white" Fender barrel-style knobs, and I plan to have the cab done in vintage Fender brown or blonde with oxblood grill cloth. The speaker is a Weber 12A150 (thanks StevieMac!). The current tube complement is 4 new stock EH 12AX7's, 2 NOS Jan-Phillips 12AT7's, a pair of JJ 6V6S, and a Shanguang (sp?) GZ34. I think I will be putting new stock Tung-Sol 6V6's in though, but it does sound awfully nice with the JJ's.
Boy - that got a bit long-winded, didn't it...
