New Express build; first time post

[Structo]

In reality I tried it on every B+ node in the supply.
My ears are not as good as they once were but in the end I didn't leave it in.

[WhopperPlate]

Well. I have some exciting news (at least for myself). I swapped out the JJ power tubes and BAM! No more horrible crackle/static distortion behind every note.

I went through the amp with a scope and wondered why I couldn't really get anything ugly until the output. After giving it the drop test a couple of times, which it survived wonderfully, I threw in the new power tubes and low and behold.

Now things are making sense. I swapped in some JJ's into my plexi build and I had a similar problem that I simply attributed to lead/solder dress. Now I know the truth.

I continuously run into this problem and forget the how tricky it can be to insure it's not the tubes. ALL the modern production tubes I had more or less caused problems, but the China tubes from the TubeTramp show no signs of these issues.

Anyways, I can crank it ten without oscillations or horrible distortion. Hurray for me.

BTW I don't know if this is normal, but I'm getting like 40mvdc to ground on p2v2.

[M Fowler]

That has me thinking because lately the EL34's are not holding up either JJ or GT.

What is currently available that is reliable?

[PlinytheWelder]

That has me thinking because lately the EL34's are not holding up either JJ or GT.

What is currently available that is reliable?

I got some JJ's coming from here: http://www.cryoset.com/catalog/index.php I've been buying from here for a couple of years now and have gotten nothing but stellar tubes...

[PlinytheWelder]

double post

[Gibsonman63]

WhopperPlate, thanks for sharing your experiences. I have been following your thread since I started ordering parts for my Express build late last month. Now that I getting close to finishing the building part of the build, it's nice to have a lot of good troubleshooting ideas in one place. Sorry for your frustration, but I am glad you got it worked out.

Sound clips?

[M Fowler]

PlinytheWelder,

I got some JJ's coming from here: http://www.cryoset.com/catalog/index.php I've been buying from here for a couple of years now and have gotten nothing but stellar tubes...

Thanks for the link.

[WhopperPlate]

Hey Gibsonman63, you're most certainly welcome. I'm glad I can provide helpful contribution to such a nice community of people. There will definitely be audio clips in the near future!

I played the amp last night at band practice. I definitely had to run my attenuator; this amp has ton's of balls and cut. There is a tremendous amount of treble, but nothing that couldn't easily be dialed out. I like the way the amp feels the most though with the volume around 6 or 7 and the treble knob past 12 oclock, get's more of a Marshall'y crunch that way, though the shimmer and tinnitus frequencies are a bit overwhelming.

I was running a 55hz deep 412 (deep marshall cab clone bought locally) with 2 ev12l (one proline 300w, not sure about the other one) and 2 ev12s x pattern. With this setup the mids and lows stand out a little boxy. I definitely will be trying some combination of celestion type speakers.

With this setup the harmonic feedback wasn't taking off as much as with my 112 test cabinet (celestion mesa black shadow). I got a chance when I first fired the amp up to plug into a 412 of greenbacks (one british and one china) mixed with mesa celestion blackshadows, and that cab sounded very good with the amp!

I was running a GE 12ax7a in the v1, old mesa 12ax7a in v2v3, and the shuguang china El34s (one biased to about 45ma, the other at about 39ma, I think around -27vdc). I'm going to try out my other stash of preamp tubes now that my power tubes are driving me crazy.

BTW one thing I noticed about the harmonic feedback; I was testing the 112 cab, using the attenuator but in bypass mode, and I was getting the feedback I so love. Well, for troubleshooting sake I removed the attenuator from the signal path, and most of my tasty feedback went away. Turns out the attenuator sitting on top of the cab was sympathetically resonating and adding a ton more harmonic feedback.

Anyways, All I need to do really is dial in the high end. After my drop tests yesterday I think I built her rock solid enough to hold up for a good while. Now I can relax and contemplate my next project muahahaha!!

[Big Jim]

Charlie,
Congrats dude! I knew you would get it right. My amp is still doing the sizzling thing just a tiny bit, but only when the Head is on the cabinet. I too, am beginning to think that I have some rattling tubes. MIght be time to order some new glass. What did Trampy sell you?
Jim

[RevD]

Congrats on getting her ironed out! It is sad that WE are the quality control dept. for most of the tubes produced these days but its a fact.
Anyway, glad you have it figured out, makes me feel more confident about someday when the money gets less funny building an Express. Thanks for sharing!

Regards,

RD

[gearhead]

Congrats! The dialing in stage is sometimes a long road (or even a dead end).

Have had a Liverpool build on hold for the last few months; only about 30 minutes from completion (wire dropping resistors to power caps to board). After that comes the obsessive-compulsive phase, lol.

[WhopperPlate]

Thanks everyone, you're all welcome!

I played the amp more tonight with the band. Amp mellowed out much more compared to the previous outing; gains a little more character every time I play her. I was playing with the bright switch engaged, volume around 6 or 7, treble 4 or 5, mid 10, bass 0, presence about 4. After switching tubes around I ended up with v1 Tungsol, v2 Mesa 7025, v3 EH12ax7. I think the China el34s are a little dull harmonically and kinda stiff compared to the other modern crap I have. I'll probably dish out the cash for some "Siemens" when I can.

Either way the amp packs a punch. I enjoy how the bass is not very boomy and leaves plenty of space for the bass player. My rhythm guitarist sits nicely in the mix with his Twin Reverb setup while the wreck just add's huge definition and really couples with the drums and bass; really sounds tight and my drummer loves it.

As of now the amp, as another forumite put it, still has a very grip and rip feel, though it is coming around the more I play and any number of things could be dialed in to suit. Leads stand out like black on white, reminds me alot of Joe Bonamassa I'd have to say (saw him live couple of months ago locally). Crystal Clear.

My other guitarist also made some recordings so I'll have some clips up hopefully before the weekend is over.

I've got the next project in the works, a DUMBLE I'll be tossing it together with a bunch of donor amps (Marshall CLub COuntry, fender bassman ten, silver face twin trannys) and extra parts, #124 based maybe HRM? I don't know it all yet.

[WhopperPlate]

Hey guys,

Here's a followup on the power capacitor tonal impact of the Express.

Lately playing the Wreck I felt it was a bit too bassy and kinda sluggish. I remembered the first night I ran the express I used my friends 412 cab (with celestion black shadows and greenbacks) and the thing sounded amazing.

Went and played the same cab yesterday with the JJ's cap and the added bass response felt overly compressed and boomy. Actually made me sound pretty lousy. I have returned almost every wire to there previous positions in the amp, before my troubleshooting frenzy, in an an attempt to return my valorized sound. With no help found, the only thing left was to put back the original cap config, with f&t preamp and sprague mains.

After the change, No more overly bassy sound and much more touch sensitivity. More dynamic, and more highs. Previously I had tested this capacitor arrangement vs the JJ can with a 112 cab with scumback m7565. The f&ts were very harsh and thin with this arrangement compared to the JJ's.

So F&T caps are indeed bright IMO, but they are a bit livelier and more sensitive compared to JJ, which is definitely much boomier. So my opinions have been confirmed for myself, but I have switched my preference back to the F&Ts (at least for the preamp filters). I can turn up the bass now!

I also feel, for the most part, changing filter capacitors made more of a difference in tone overall than changing power tubes. Quite dramatic.

[RJ Guitars]

Charlie,

That is a great tale of technical perseverance. When I read all the tales of Ken Fischer slowly dialing in amps and madly swapping out tubes, it reminds me that these beasts are not for the faint of heart to sort out and even the master had to work at it. There are also tales of KF giving up on some of his own creations and dismantling them, so anytime you make one work right it is a great accomplishment.

Congratulations, you have provided us some great insight into the dial in and certainly those in line to build an Express in the future will have your posts to learn from.

rj

[WhopperPlate]

Thanks RJ, couldn't have done it without you!