Junkyard Express !!!!

[dansamp]

first time posting here
been a member for a while but this is my first post
hello everyone my name is Dan.
anyway I built an Express using stuff I had laying around the garage
the chassis and power transformer are from a Traynor Bassmate and the output transformer is a Stancor 3800 using a 5k primary
not sure how it will sound with EL34 tubes but I have some old stock 5881 and I fired it up with some 6V6 ' s
have to sort out the preamp tubes
turned out quite well considering the stuff now I wish I had some better resistors
I am using orange drop 418's in the preamp section and one 715 and one 716 in the P.I.
I swapped out the .002 in the 3rd stage for a .01 418
the treble cap is a 560pf and I have a 390pf and 100pf on the bright switch
this is one bright amp
don't have a closed back cabinet (which doesn't help
nayway hope the photo's show up
let me know what you think

Dan....

[dansamp]

a few more pic's

[funkmeblue]

looks good, what's your plate voltages like?

[skyboltone]

Good job. Will a Fender cap can cover those?

[dansamp]

looks good, what's your plate voltages like?

thanks ,
will try to post some voltages tomorrow night
I think B+1 is about 410v
the 5881's are biased at 36ma
I can pretty much play the amp with all the tone knobs off and the volume on about 2 1/2-3 and its pretty loud hooked up to my mini bluesbreaker using a celestion blue and a gh30

[dansamp]

Good job. Will a Fender cap can cover those?

thanks,
not sure if it will fit but I have to do something because so far today I have been zapped three times


....and still alive to post about it

any suggestions on caps to use ??
the orange drops were some I had left over from a 5E5 Pro clone I built about 8 years ago
I pulled those out and installed some Mallory's and the Pro clone sounds so much better
I see lots of TW clones with orange drops so I figured I could use them

also the middle knob is not very effective, I didn't have a 22k pot so I used a 10k pot with a 15k resistor across the two outer lugs

the first TW type amp I built was in a Masco P.A. chassis and it was true point to point,
cathode biased because I didn't have enough room in the chassis for fixed bias ,
but it wasn't laid out very well and although it sounded good it had a very loud hum which I could not get rid of,
so I put it aside and built this one
anyway sorry to be so long winded

Dan.....

[Fischerman]

Your mid pot effective value is 10k in parallel with 15k or only 6k...that's not gonna do much. It will probably work fine when you get a 25k pot.

[CaseyJones]

the chassis and power transformer are from a Traynor Bassmate

not sure how it will sound with EL34 tubes but I have some old stock 5881 and I fired it up with some 6V6 ' s

The Bassmate is an EL84 amp stock, isn't it? Or did Traynor use something really weird for output tubes? Searching the memory banks, that's two things that come to mind about the Bassmate.

Although Traynor used some pretty heavy duty iron I don't think you have enough filament current for EL34s. I'd be cautious there.

Spend some of the dough you saved for a 25k pot and a cap can and you're all set!

[dansamp]

Your mid pot effective value is 10k in parallel with 15k or only 6k...that's not gonna do much. It will probably work fine when you get a 25k pot.

do you think that is also affecting the bass pot??
it seems I don't have a lot of bass control

[dansamp]

the chassis and power transformer are from a Traynor Bassmate

not sure how it will sound with EL34 tubes but I have some old stock 5881 and I fired it up with some 6V6 ' s

The Bassmate is an EL84 amp stock, isn't it? Or did Traynor use something really weird for output tubes? Searching the memory banks, that's two things that come to mind about the Bassmate.


this Bassmate used 6V6 power tubes
it is the same version that Mark Huss converted into a 6V6 plexi type amp on his website

Although Traynor used some pretty heavy duty iron I don't think you have enough filament current for EL34s. I'd be cautious there.


that's why I didn't hook up the stock pilot light to the heater wires
I used a 120v pilot light

Spend some of the dough you saved for a 25k pot and a cap can and you're all set!

I was trying to use stuff I had lying around just to see if I could do it with out buying anything
I ended up having to pick up the diodes at RS and the pilot light

[Phil_S]

Nice! Those A-3800's go for a good price on eBay when they come up for sale.

IMO, those exposed caps are too much of a safety problem and need to go. Can you locate them in that corner by the preamp tubes? Just move the heater wire out of the way. I realize this means relocating all of the B+ wires and may not be practical. If not, you should spring for can caps for proper and safe top mounting.

Angela sells a 40-20-20-20 for a very reasonable price. One will manage the B+ rail downstream from the standby switch perfectly and a second one will do the upstream chores if you use one 40 section and a pair of 20's in parallel. Or get the one that's 50-50 and be done with it.
http://www.angela.com/

[dansamp]

yeah I agree with you phil,

the Stancor I pulled out of a friends tweed Bandmaster, he didn't have any use for it so he said I could have it

like I said I wasn't expecting it to turn out this well
it fired right up without any issues no squeeling or hum etc.
quite a bit of hiss with the volume up past 10:00 0'clock but I attribute that to the C.C. resistors
I will try to find some type of cover for the caps
for now I need to scavange the mid pot from my first prototype Masco build
it's settling in quite nicely, I tried it later last night with my Melody Maker reissue that sports a Lollar Chicago Steel pick up
I am wondering if I should keep the 418 OD caps
or does anyone have any other recommendation

Dan.....

[dansamp]

ok guys
for those curious here goes:
B+1 420v
B+2 416v
B+3 351v
B+4 331v
B+5 313.6v
bias -40.0v
-----
V1-1 221.7v
V1-3 1.907v
V1-6 195.2v
V1-8 1.603v
--------
V2-1 298.3v
V2-3 2.997v
------
V3-1 278.1v
V3-2 121.5v
V3-3 168.5v
V3-6 281.0v
V3-7 112.9v
V3-8 168.5v
-----
bias v -40.9
----
bias current
V4 36ma
V5 34ma
--------
V4-1 .036v
V4-3 415v
V4-5 -39.8v
V4-6 413v
-------
V5-1 .034v
V5-3 416v
V5-4 413v
V5-5 -40.0v
V5-6 414v

so there it is

Dan.....
that is with 5881 power tubes