Express Build Completed...Holy Sh!t !!!(Updated - Pictures)

[strato17]

Let me first say that before I started this build, I had never even picked up a soldering iron. Now I have a SCREAMING EL34 amp! I cant thank all of you guys enough for your help, especially Ron Worley. I built my express using his BOM and Build Guide exclusively. From the day I first ordered parts, it took me about 6 weeks to complete the project. Alot of that time was spent waiting for backorderd parts

I am only 19, I play guitar for a living and go to university. Before this build, I didnt know the difference between a diode and a transformer. I picked up a copy of The Guitar Amp Book by Dave Hunter, which helped tremendously.

This amp sounds UNBELIEVEABLE! So Rich! So much sustain! My 69 335 just sings with this amp! No squeal, microphonics, or hum whatsoever!

Dont feel intimidated if you dont know anything about electronics. With the help of the BOM, Build Guide, and the members of this forum, you can easily complete this build.

Lessons I Learned on this Build:
1. It DOES matter with Output Transformer Plate Wire you wire to a certain power tube socket... they are not the same.(lots of squeeling ocurred)

2. Soldering to a copper buss bar is a pain in the @$$... unless you have a super high powered soldering iron.

3. Burning PVC insulation with your soldering iron smells terrible.

4. Burning skin with your soldering iron smells even worse.

5. Check your pots before you install them. The 1 meg pot for my treble control actually has a max resistance of 10 meg... the first quarter turn is 10 meg to 6 meg, then it jump to 1 meg, and decreases value for the rest of the turn. And I got the high quality PEC's

6. Radioshack soldering irons are garbage. I went through two in this build(first one exploded with sparks... so pretty.)

7. Dont check your plate voltages across a 1 ohm resistor to ground. (learned that one the hard way)

A Few Tube Questions

Layout
V1 - Mullard, Blackburn Code, Long plates
V2 - Brimar
V3 - Sovtek LPS, balanced triodes from KCA
V4-V5 - GT EL34M #4, plates at 400 and 404

Is my preamp selection ok for a wreck? Is it worth the money to buy a NOS PI tube?

I have 43mA bias current on my EL34M's right now.... is that ok? I dont see any redplating, and they sound thick, tight, and full.

Thanks to Ron and the Amp Garage Community!
Chris

pics and soundclips(hopefully) to follow soon.

[declan]

Congratatulations Strato

theres nothing quite like jumping straight in the deep end of a dung pile and coming out smelling of roses

So give yourself a big pat on the back and dont underestimate what you have achieved, I know many long term plug solderers that wouldnt dream of having a go at an amp like this, and for the ones I know thats probably a good thing

Just as a matter of interest what speakers are you using, and how are you finding the VOLUME

[Lonely Raven]

Wow, congrats! Jumping into a TW as your first build is pretty heavy!

I need to look at Ron's build guide...it must be pretty good!

[Tubetwang]

Wow!! first build?

Good shoe!!!

I wish i'd built an Express at 19...

Goes to show that it's never too late...

As for your questions... I am not experienced on the Sovtek PI so i don't know but my Espress is biased at 45mA and i like it...

[drhulsey]

... before I started this build, I had never even picked up a soldering iron...

It just goes to show that it's better to be lucky than good
My beginner's luck was even better than yours. I got my OT leads right– no squealing
Allynmey has seen bias currents of 49 mA on some real Wreck's, so you should be fine.
Congratulations on building a great amp

[rooster]

Yes, congrads are in order. And you are very right to thank Ron, he put in some serious time on that project, and it does make the task easier -but don't forget to thank all the other people who contributed I think even more. Without these 'pioneers', BTW, people who actually own, or have worked on one (many?), and who have bothered to share what they have learned with this community, Ron's work wouldn't exist. ....OK lecture over.

Anyway, as to tubes, if you are in Europe (sounds like you might be?) look for the Tungsram branded (Hungarian) tube for V1. You might run into something that we would never see. That V3 is not bad for new, BTW, I like it in mine. V2 is no opinion, everything seems to work in mine - as long as it is USA or NOS Euro that is.

Have fun and watch your ears. At 19 I never had anything as loud as this, you could hurt yourself pretty quick.

[rooster]

OH, Plano TX? I guess it was when you used the word 'university', I only hear that from my European friends. Anyway, whatever your local, seek out that Tungsram. And good luck in the university.

[strato17]

OH, Plano TX? I guess it was when you used the word 'university', I only hear that from my European friends. Anyway, whatever your local, seek out that Tungsram. And good luck in the university.

Haha no problem Rooster. That is funny that you thought I was European from that one word. My canadian friends say that all the time.... I must be hanging around them too much!

Yes, congrads are in order. And you are very right to thank Ron, he put in some serious time on that project, and it does make the task easier -but don't forget to thank all the other people who contributed I think even more. Without these 'pioneers', BTW, people who actually own, or have worked on one (many?), and who have bothered to share what they have learned with this community, Ron's work wouldn't exist. ....OK lecture over.

Ditto That. We would all be in the dark if it wasnt for those people who actually own the amps.

It is indeed loud, but I dont find it too loud. I wouldnt want to put my head in the direct path of the cab though

I have two of the Scumback M75 65-watters on the way... they should be here in 2-3 weeks. In the meantime, I'm using a convertible Weber cab with a Blue Dog and 1230-55(G12H30). The amp sounds awesome through this cab, even though the Blue Dog has an insane amount of voice coil rub(need to get it rebuilt). I think the scumbacks will sound even better with the amp... I can't wait!

Does anyone know a good source for Tungsram 12AX7's? Will I notice a big difference between the Mullard and the Tungsram?

[Ron Worley]

Rooster- You beat me to it.... Although I do have an EE degree and have been working on Fenders for several years, there's absolutely no way I could have done it without the guys here on the forum- Skyboltone, Allyn, UR12, Gearhead, V486 (David Bailey), Noel Grassy, Funk and others that I'm sorry if I missed calling out.

The BOM was Gearhead's that I added info to, and the build guide a combination of pouring though countless posts, asking a bunch of (probably) annoying questions and the process of doing my own build (the latter of which was probably then most educational of all).

Chris, I was glad to be of help- you're exactly the kind of guy I did it for... glad it worked out, and you had the exact same reaction I did when I fired it up the first time- HOLY SH!T!!

Ron

[bcmatt]

Haha no problem Rooster. That is funny that you thought I was European from that one word. My canadian friends say that all the time.... I must be hanging around them too much!

I'm Canadian and am all of a sudden wondering what word Americans use instead of "university". Do they just call it "Uni" like the Aussies and Kiwis?

[morcey2]

Haha no problem Rooster. That is funny that you thought I was European from that one word. My canadian friends say that all the time.... I must be hanging around them too much!

I'm Canadian and am all of a sudden wondering what word Americans use instead of "university". Do they just call it "Uni" like the Aussies and Kiwis?

We usually say 'going to college' or 'going to school'. Also, in many cases, called 'tamping Mom and Dad's money down an alcohol-soaked rat-hole.'

College has a different meaning in the US than most other places in the world, I guess.

Matt

[kindred]

here in canada at least, colege and university are two different things. university is like high class colege... if you wanna be a teacher for example you would need to go to university not colege

[Structo]

Europeans say, I'm going to University.
Yanks say, I'm going to the University.
But usually we say the universities name, like, I'll be going to Oregon State (university)
One of the other universities here is University of Oregon.
So they say, I'm going to U of O.
Semantics.

[drz400]

5. Check your pots before you install them. The 1 meg pot for my treble control actually has a max resistance of 10 meg... the first quarter turn is 10 meg to 6 meg, then it jump to 1 meg, and decreases value for the rest of the turn. And I got the high quality PEC's .

My guess is you are not reading your meter correctly or had some dirt between your probes and the terminals. I would check that again, sometimes meters will autorange and you can misread them as well.

[Allynmey]

Great job Chris...congrats. Got any pics?