New Express build; first time post

[WhopperPlate]

Hello everyone! Thanks for having me on the forum!

I have just finished building my Express clone and I'm anxious to fire this baby up! I have provided some clips for everyone to judge and scrutinize appropriately. Hopefully everything looks good to all the experts. I think I did everything right, but if there is anything that seems fishy I would very much appreciate the notice.

Thanks to RJ for providing the majority of components (pacific transformers, boards, chassis, resistors + signal caps). I can't say enough about the guy, real nice fellow! A joy to talk to, follows up every email quickly! I highly recommend his services.

[ampgeek]

First post.....maybe. First build....highly unlikely!

Seriously, looks really nice. Well done!

I only scanned for obvious mistakes and nothing jumped out at me.

The only lead dress "issue" that I saw was the power tube signal grid lines criss-crossing. I seem to recall seeing/reading somewhere that this might be troublesome.

Rock on mate!
Dave O.

P.S. +1 on RJ! A true gentleman.

[Big Jim]

Hey Whopperplate,
I wasnt familiar with your user name, but the amp looked familiar. How's it going Charlie, did you start testing yet? I am winding down on my build as well. Good luck on your fire up!
Jim

[WhopperPlate]

Thanks so much for the kind regards!

Ampgeek, thanks for the heads up; I will correct the problem asap.

I have built two other amps; a superlead and a 18watt Marshall. I wanted this one to look as nice as possible, so the positive remarks are much appreciated.

Hey there Big Jim! Will likely fire it up tomorrow!

Charlie

[M Fowler]

Nice build and welcome aboard.

Yes rj is a great guy and always takes care of me and many others.

Mark

[WhopperPlate]

Thanks Fowler!

[Noel Grassy]

Whopperplate, Great looking job mate! If you can would you mind putting your measured voltages in this thread? It'd be informative to see how yours compare with the few we already have. Thanks
and welcome to the Amp Garage.

Noel Grassy.

[JamesHealey]

Third build? cool!!

Looks impressive very good clone, Never really been one for exact clones, pretty much impossible here in the UK the price to order some of that American stuff is just pointless like the big Mallory Electrolytics etc.

[WhopperPlate]

You're all too nice! Thank you all!

I will post audio clips and voltage measurements asap.

The Mallory caps were just too expensive. I used mostly what I had lying around; sprague and F&T caps. If it doesn't feel or sound right I will consider an upgrade.

Heard Glen likes Sozo royal caps, any other preferred caps?

Anyways, I've got a good feeling about this one and eagerly await testing tomorrow.

Again, thanks for the kind remarks.

Charlie

[geetarpicker]

When I first tried the Royal caps in an Express they had a noticable darkening effect and added compression. However I noticed once they broke in they actually opened up a little in the top end. On the gig the extra compression was almost too much, keep in mind that might be just as much due to to having two in series to get the voltage rating. I went back to using the Mallorys in that amp in the end, and put the two Royals in my '68 Superbass 100.

[WhopperPlate]

I really like the Sozo Royals and found similar results that you experienced with my own superlead. They start out rather dark, but brighten up later on. With the vintage sozo caps and the royals it was so dark and compressed at first that I had to switch back to standard sozo caps while the royals broke in.

BTW as it seems with most express builders on this forum, I owe a certain amount of gratitude to geetarpicker. Wouldn't have built one myself if it weren't for your wonderful sounding youtube videos. Thank you Glen!

[Big Jim]

+1 on the gratitude for Glen. I remember my Jaw dropping the first time I heard his playing and his Express! It surely got my attention. Now if I could just finish the one I'm building.....
Jim

[WhopperPlate]

So I fired her up today, but I'm getting unusual bias readings in standby. I don't know if the bias pot is wired wrong or what, but I'm getting -27v at noon -24v at max and minimum settings on the bias trimpot. Tried replacing the pot but that didn't help.

I have the center lug tied to the bias resistor and the other two to ground; that's how it looked wired from the archive photos and is what seemed logical considering the turret layout, but I noticed the layout chart shows the wiper connected to ground instead.

Obviously I'm not a college grad electronics engineer.

[PlinytheWelder]

So I fired her up today, but I'm getting unusual bias readings in standby. I don't know if the bias pot is wired wrong or what, but I'm getting -27v at noon -24v at max and minimum settings on the bias trimpot. Tried replacing the pot but that didn't help.

I have the center lug tied to the bias resistor and the other two to ground; that's how it looked wired from the archive photos and is what seemed logical considering the turret layout, but I noticed the layout chart shows the wiper connected to ground instead.

Obviously I'm not a college grad electronics engineer.

The wiper and one end lug both get tied to ground, the other end lug goes to the resistor.

[WhopperPlate]

Thanks. I figured it out; had to twist and tweak my trimpot legs to make it work correctly. Bias sweeps from -25v to -35v. All other voltages are looking swell, so I'll install tubes tomorrow take it from there.

Like I said, I'll have the voltage chart and clips asap.