Attempted Simplification of the Express - Non Traditional

[Miket]

Yes I am also interested in this. Seems like a good start for a first trainwreck build

[M Fowler]

Yes the PCB to me was very simple to build and sounded good on first fire-up.

We will have to wait and see what rj wants to do regarding offering at least the boards.

Mark

[RonnieJ]

Yes the PCB to me was very simple to build and sounded good on first fire-up.

We will have to wait and see what rj wants to do regarding offering at least the boards.

Mark

Are there instructions or at least a layout included with the pcb version from RJ ?

[rock_mumbles]

That's being worked on over here ...
https://tubeamparchive.com/viewtopic.php?t=18831

[Koop]

In these photos I see what appears to be the 1k 25 watt resistor mounted to the chassis with screws. The only 1k 25W I have is a cement type, no metal housing or any way to fasten to the chassis. What is the best way to install this in the revised PCB build?

[M Fowler]

Koop either get the metal base 1k/25w resistor or make a small eyelet or turret board and place the board on the right side of your output jacks in that bare space on the back panel.

See the red board in my 18w amp.

[Koop]

Thanks Mark, I'll rig up something similar.
EDIT - I decided to order aluminum housed resitors from Digi-Key since I could use a couple of other items as well. My $11 order will probably cost $20 by the time it ships!

[dorrisant]

Just a little update...

After a few months of breaking-in, my PCB Express is very quiet and stable... quieter than any of the Fenders or Marshalls that make their way through here, but not quite as quiet as my Rockster.

It is very sensitive to any vibration applied to the chassis. You can hear the mechanical snap of the bright switch through the amp. It is not a bad thing as long as it is isolated from any vibration. I usually sit it up on a pillow (must find a cooler method), and never on top of the speaker cab. We discovered a weird octave thing going on one day at a show... it was picking up the vibe from the cab resonance. Put it on the floor and it went away. I was aware of this possibility and it wasn't that big of a deal.

Just saying this because even though this is a very stable way to build this circuit you can still pick up funny noises if you don't pay attention to noise/vibration sources.

That said, this amp sounds gorgeous, clean all the way to flat gettin' it. The only complaint from anyone is that it is too loud as is... so I pass out earplugs!

Thanks and best wishes to rj!

Tony

[M Fowler]

Thanks Mark, I'll rig up something similar.
EDIT - I decided to order aluminum housed resitors from Digi-Key since I could use a couple of other items as well. My $11 order will probably cost $20 by the time it ships!

Yeah isn't that the truth so I usually wait until I have a higher dollar parts list to fill before I order from Money pit Mouser.


Mark

[M Fowler]

Tony,

Glad your amp is working out so well except for the fan earplugs hard to put your band logo on such a small item. Better go with Vulcan ear type.

Still the PCB type layout to me was such an improvement for stability. To eliminate what your going through I had to use lower gain tubes it's a must for most situations. Better get one of those garden knee pads to use between the head cab and speaker cab.

Mark

[dorrisant]

Thanks Mark.
That is a good idea... I'll have to look for something like that. Much more low-profile than a over-stuffed throw pillow!

I am still thinking of using ampdoc's idea of attenuation via dropping power tube heater voltage. I tried this with a huge variable resistor and it worked but is too large to fit in most amps. I may have to get a VVR from Dana to do the scaling... just on that heater voltage.

Has anyone tried this?... just looking for a starting point. Seems like someone did... Hans maybe?
I have never even used VVR before. I know how it works but getting it to scale the smaller voltage and rectifying it to dc are two issues to address.

Tony

[RJ Guitars]

I hadn't played this amp much since I finished it but I got a call from a guy looking for an Express to be used for guitar students learning the fine art of shredding... He owns a little guitar studio in Texas and is a well respected music teacher in his part of the world.

This particular amp went was pretty cool sounding as you cranked it up but I felt like it was overly compressed as I really cranked it hard. I wanted something that just added more flavor rather than just sounded more compressed so I decided to swap out the original Edcor OT for a more Express like one... I have a lot of OT's around so i chose a Triad S-60 which is rumored to be the same as a Stancor A-3801. I can neither confirm or deny that fact and it did not sound extremely different than the Edcor I took out but it was a good sounding amp so I buttoned it up and sent it off to the studio.

They made me a shred demo the same weekend they got it and it is really one of the first times I recall hearing shredded Wreck music. He gave me all kinds of apologies for the sloppy playing and quick and dirty sound of the clip but I thought is was very cool and certainly something I could never have pulled off.

Enjoy!

[martin manning]

Some classic licks in that MP3! Very cool indeed!

[M Fowler]

Good job on that amp rj, I take it they are not sending the amp back to you

[Reeltarded]

That sounds freaking great a little like the face of Jeff's killer Token that I liked so much.

Dry and fat!