New Express build with pictures!

[Cliff Schecht]

Mmmm... Amp sounded fanfuckintastic at practice today. The other guys kept double taking when I would hit a bend and hold it for 2 minutes straight, no exaggeration . It really is amazing how versatile of a design this is, not only with the mean to scream aspect but also with how maneuvering the tone control also completely changes the sound and mood of the amp. I've almost never touched my tone controls in the past, aside from the occasional Wes Montgomery style jazz lick, but the amp really mellows out with the tone control turned down about halfway (not sure of the Tele's taper but seemed about 50%). Turn it back up and you can continue cutting off heads. Gotta love how well this amp cuts through the mix!

[geetarpicker]

There you go, that's the way you do it! (working the geetar knobs...)

[Cliff Schecht]

I'm going to have to reposition the knob on my Tele so that I can get consistent cleans without having to guess, this doesn't work so well mid-song. The trick I like to use is to position the screw notch on the knob so that the guitar gets the *perfect* clean sound with the notch at a 12:00 position. The knob was tweaked for my previous 'Wreck build but this one plays a bit different although it sounds much better as well.

Since I haven't played this amp a whole bunch, I'm still learning the knobs and where they like to be set. So far I have: 500pF cap on at all times, volume on 5 (out of 10), treble on 2-2.5, mids on 3, bass on 7 and presence on 2 or 3. The attenuator is running at about 35-40% which doesn't really kill the tone, just cuts down the volume to a much more usable level.

I ditched the 6V6's early at practice soon too once I realized that the clean volume is cut down drastically when using these. What a shame, they had a great distortion sound, but then again the Sylvania 6CA7's had an even better distorted sound and cleaned up great! Fun amp to play, you're lucky you have an original Glen . I think my choice of paper in oil/polystyrene caps was a good one though, they really do sound quite smooth and I think may help cut down on the harshness a bit as well.

I'll have some clips from a bar show soon and, hopefully, will have the head cab in by early next week so I can tote this thing around safely and conveniently!

[Cliff Schecht]

Here are some soundclips. Listen to the second song and make sure to listen to the solos in the songs. I simply can't do this amp justice . It's funny how good all of these recordings sounded in the studio and bad they sound once produced and mastered.

http://www.reverbnation.com/#/eddymcfre ... egetreadys

[RevD]

Here is a page I found for a bucking transformer to cut the voltage a bit for vintage amps (and in many of our cases lower heater voltages and also for some Hammond transformers that were tested at 110 volts and put out a tad to much B+). This has probably been posted here somewhere before but for convenience, this circuit by R.G. Keen:

http://www.geofex.com/article_folders/v ... ntvolt.htm

Regards,

RD

[geetarpicker]

I have one semi permanently mounted to the top of the chassis on my '68 Marshall Super Bass 100. Brings the B+ down to a range that even modern tubes can easily handle.

[azatplayer]

Love the look of the pio caps, i have some on hand and have started my first express build, but have it setup with poly's. Very tempted to try paper first, love the rusky k40Y-9's in my other amps.

[Cliff Schecht]

Yeah I'm sold on the amazingness of PIO caps. They not only sound consistently fantastic (read: transparent) but look great in builds as well. All of my latest scrap pile builds have been with a variety of cap types but I always find myself coming back to PIOs and polystyrenes for signal/coupling caps.

[PlinytheWelder]

Yeah I'm sold on the amazingness of PIO caps. They not only sound consistently fantastic (read: transparent) but look great in builds as well. All of my latest scrap pile builds have been with a variety of cap types but I always find myself coming back to PIOs and polystyrenes for signal/coupling caps.

Agreed, I used PIO's and polystyrene in mine and it's very smooth. so much so, I'm only on the 100pF bright cap all the time...

I'm a big fan of the Russian PIO's, too and have another 30 waiting at the post office now...

Got 'em in all my guitars, too.

[azatplayer]

Yep got em in all my guitars too. Just discovered styrene, impressed sofar. Got some 470pf in pio as well, getting rid of the troublesome micas.

[schorn]

I had the same squeal that was explained in the begining of this thread. When I disconnected the NFB wire the squeal went away. The prescribed fix for this as stated earlier was to swap OT primary wires. Does this mean that I swap the current wires. I am really asking do I desolder the OT primary that is on V5 and solder to V4 and vice versa.

[Structo]

Yes but if you have already cut the primary wires to length, you may not have enough to swap them without adding on to one side.

A more simple approach is to swap the two wires leaving the phase inverter.
That would be the two wires coming from the 220K resistors that go to the power tubes grids at pin 5.
Swap the wires at the 220K resistors and you should be good to go.

[schorn]

Swapped the two wires on the resistors on pin5, reconnected the NFB wire and the squeal is gone. Thank you for your solution.

This was a first build by my 14 year old son. Even though I find the hiss produced at an acceptable level, we would like to reduce.

The first tones from the amp are great, sustain like I have never had in any amp I have ever played. All the reading I have done states that this is a loud amp. That is an understatement.