5E3 for 6V6/6L6

[tubeswell]

Cabinet finished - bar covering

Got home from work early, trimmed the dowel ends, sanded everything square, then let loose with the hand router and then tidied up again with the orbital sander - about an extra 2-3 hours

Put some hessian on the front side of the baffle (probably about NZ$2 worth)

Tried a G12M for fit ($NZ280 - got it at a bulk-purchase price - normally $320 here). There's just enough room the way I've got the speaker positioned for the chassis (squeezed down the bottom and slightly over to one side) for tubes to fit in - allowing for 6L6 size - I'm not sure about running the G12M with 6L6s, but it'll be okay with 6V6s).

I'll cover it with some of that Black & White fleck gingham thingy fabric when I get a few spare hours. I like the way it looks on my previous amps and I've still got a bit lying around, plus it hides the fact that I haven't done finger joints :-)

[tubeswell]

Should I cover it in fabric?

Each time I ask this question with a new amp, I have covered whatever it is by the time I get to my next post. Ma te wa (maori for "Time will tell")

Anyhow I finished wiring the chassis today and double-checked the circuit with my meter from back-to-front checking for any unwanted shorts or missing connections, and as I couldn't find any I hooked it all up (all up about 4 hours or so).

Hmmm..., was I gonna bring it up carefully rectifier first? I decided to hell with it and plugged them all in and fired it up.

With a NOS Toshiba 5Y3GT (~$NZ40ish) running a pair of JJ 6V6s ($NZ68.70/pr) and a Mullard 12AX7 (can't remember what I paid for that) in the PI and EH12AY7 in V1 (NZ$28) , the B+ came out at 373 with a plate voltage of 371 - no smoke or red-plating. (Another hmmm..., was this a 5Y3 GT or somethingelse disguised as a 5Y3GT?)

Anyway after a minute or so running, it settled back to plate voltage of 363 (funny how it does that) with a cathode voltage of 22 (through a 10W 255R resistor) and I estimated the tube dissipation at that point to be ~14.7W. Even though they are JJs, I thought this was a bit high so I zenered the HT CT down to give a plate voltage of 354 with a Cathode Voltage of 21 (and that's 13.7W).

So then I plugged in my strat for an hour or so, which is where I've been till I could tear myself away. Well I'm not what you would call a religious man by any stretch of the imagination, but if there is a tone god, he was in my new amp tonight. So that's it - for about $1G of parts and 1 month's worth of part-time building = tone heaven.

How much difference to the carbon comps make? Well I'm not exactly sure. The amp sure sounds fantastic (albeit a bit hissier than my 5G9, which has metal film resistors, is fixed bias, and altho' having a similar v1 stage, it has a completely different PI/driver). I reckon I'd have to build a duplicate of either one with the other type of resistors to begin to get a feel for this question. But can I be bothered going to those lengths? - not sure about that for now (but anything is possible).

I have a pair of JJ6L6CG and a 5U4GB and a 5AR4 handy (the recto winding is rated at 3Aish , and the heaters at 4Aish), so I could easily check how it runs with 6L6s, but I think I'll enjoy running the 6V6s for a while.

[tubeswell]

Gingham Suit

Well I had a bit of spare time today after mowing the lawn and I had a few metres of the same material I did my 5G9 and 5F2A in. I am getting a quick technique with this now, so it probably only too me about 4 hours to cover it - glued and stapled.

Gingham tweed - NZ$16/metre
Weldbond Glue - NZ$10 bottle

I got to branch out into some other colour schemes (when I've finished my stand alone reverb, and maybe then a tweed bassman)