Express Combo Build

[jeff12]

OK now you're just being a showoff .

If I wanted to be a showoff i would have posted these.

[RJ Guitars]

Dude that's not fair!

[Zippy]

I thought it was some really good photoshopping.

Seriously tho', you've turned out some nice work. Kudos!

[hans-jörg]

Hi,
utterly beautiful.
Could you scale it for me, please?

Hans-Jörg

[jeff12]

Hi,
utterly beautiful.
Could you scale it for me, please?

Hans-Jörg

???? Do you need the size of the cabinet?

[hans-jörg]

No, I spoke about weight. This wood looks very heavy

Hans-Jörg

[jeff12]

No, I spoke about weight. This wood looks very heavy

Hans-Jörg

46 pounds, my Dr Z Maz 18 is 55 pounds so it is 9 pounds lighter than my Z.

[jeff12]

Ok it has been a little while since I posted a progress report on this amp.
Worked on getting best tone from this amp for a little while and had it sounding good. Decided to experiment with some new EH El34 tubes. All was well until tonight had bias set at what seemed reasonable current and then the smoke started to pour out the amp. Changed tubes to old stock rft's and re biased the amp and all is well again. I guess medium grade EH el34's won't handle as much current.
Here is a short clip of what the amp sounds like.

[andresound]

Hi Jeff12,
Stunning build, well done!
I am about to build an express from RJ. Please tell me your take on the difference in sound between the v30 and Creamback.

[jeff12]

Hi Jeff12,
Stunning build, well done!
I am about to build an express from RJ. Please tell me your take on the difference in sound between the v30 and Creamback.

Vintage 30 has 3db more sensitivity so it's a little louder. Creamback 65 has a different midrange and to me less bass response. Both sound good but different to me. I switched the speaker you hear in the clip is a Weber Blue Dog
with a hemp cone and pre rola dope treatment. This speaker sounds better to me in an open back single 12 combo. Warmer with better bass response and less harsh on the high end. Check youtube for sound clips of Celestion speakers comparison.

[jeff12]

Update on this combo build. Added a VVR circuit to this combo tonight. First adjustable bias VVR I had work and be quiet. Fit well in the end of chassis.
Not very nice to look at but it works. The next one will look better I Hope.
Sounds best to me just under half or more on the level, turned down too much and the amp sounds like hell. It makes for a more usable combo with out using an attenuator, as long as you don't go too low. Tomorrow may work on setting the low point voltage, that may help.

[jeff12]

Worked today on cleaning up VVR install. Changed low voltage point resistors to set low voltage at 150 volts and going up to 405 volts max. This seems to be a good range for this amp. The amp does not get flabby at low VVR settings and still is a low enough volume level to be very useful. Thanks to Richie also for suggestions on capacitor values for the input, helped to quiet static and improve sound. Made new mount for VVR potentiometer also.

[jeff12]

Whoops found an error in input jack wiring, set range to about 15%, five more than stock. 150 volts was way more than needed on the low side.
Sounds great at all settings now. No more low end problems.

[johnnyreece]

Man, that's sweet looking. I like the creativity with the VVR location.

On a side note, I've got my express-like project going, and I'm thinking of the blue dog/silver bell combo. Think the SB will add anything?

[jeff12]

Man, that's sweet looking. I like the creativity with the VVR location.

On a side note, I've got my express-like project going, and I'm thinking of the blue dog/silver bell combo. Think the SB will add anything?

Great combo of speakers, I like the two of them together. They say the blue is vox sounding and silver is more marshall sounding. I have had multiple versions of both and have an alnico silver with hemp cone on the way to try now.