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Topic: Latest project Vibrolux clone |
Ken Fox
From:
Nashville GA USA
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Posted 16 Oct 2008 9:37 am |
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I have 3 pots on order and I will have the chassis done. The cab will be from Mojotone and the speakers will be Weber Vintage series, Ferromax, ceramic, 8 ohm at 25 watts.
Lots of fun! Lots of time to build one of these compared to the tweed clones I have done.
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Bill A. Moore
From:
Silver City, New Mexico, USA
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Posted 16 Oct 2008 1:40 pm Thanks for the pic's!
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| I am waiting for my final batch of parts for my Twin project, and your pic's will help with my layout. I have noticed on some of the silverface amps, that there is another wire wrapped around the wires from the cap board. I guess it's not used on the blackface amps, if I have a hum problem, maybe I'll need to look at that. I do plan to run shielded wire from the input jacks to the tubes, and back to the volume pots.Thanks again for the wiring pic's, Bill. |
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Rick Johnson
From:
Wheelwright, Ky USA
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Posted 17 Oct 2008 3:46 am
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Ken
Great job, I'm sure its gonna be
a rockin amp.
Here is a before and after pic of
my Super Reverb.
Again great looking work.
Rick
www.rickjohnsoncabs.com
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Jim Sliff
From:
Lawndale California, USA
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Posted 17 Oct 2008 5:00 am
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OK, this is getting me all worked up; the last complete build I did was a super Reverb from a flamed-out hulk that had cabinet, chassis and transformers, plus the cap can cover and most of the pots and jacks. I have a similar "found in dumpster" Ampeg V4 head...so I guess it's time to start a new project!
Ken - your layout and lead dress is pure artistry. It's nice to see when someone takes the time to not only make it functionally nice, but with clean lines, straight wires of the right length and a *really* good twist on those troublesome filament wires. I may actually (on this hunk I have) install a DC transformer for the filaments - I've read enough theory about it and have seen several examples, and since I wont' be wrecking a vintage amp it's worth a few bucks for a small transformer.
Bill - I'm sure you know, but if you don't - only attach the shield of the wires you mentioned to ONE end at ground, otherwise you'll be chasing hum 'til the cows come home!
_________________
No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Ken Fox
From:
Nashville GA USA
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Posted 17 Oct 2008 5:28 am
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Wow, Rick! What a nice cleanup on that Super Reverb. That is as much a challenge as building a complete amp. Did you use a board wash or pull the components for clean-up?
Jim, I use the old battery operated drill to twist the filament wires. Learned that years ago when we were building sound racks in commercial work.
I keep pictures of amps I have worked on so I used records I kept on another Blackface Vibrrolux Reverb for reference.
The wire comes from New Sensor, the best I have found and it is also true push-back wire. I do not use shielded cables in these amps. You are so right about grounding one end only! That was referred to as "telescoping shields" in the old days!
I read a lot about the outside foil on these type caps (mallory 150). They are not marked and so far I have not heard a difference. I will check some with Aiken's scope method. Hopefully it will not be an issue.
A real chore getting all the parts together. Transformers, chokes, pots, resistors (carbon comp), Switchcraft and Carling parts, correct tube sockets and more. It actually will cost more than the kits Weber and Mojo sell. Then again, a lot of parts are an upgrade to their kits.
I can't wait to fire it up. More later!!! |
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Rick Johnson
From:
Wheelwright, Ky USA
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Posted 17 Oct 2008 6:07 am
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Ken
Everything came off, I put a couple
of the old brown caps back on.
I think the amp caught fire?
The output tranny was fried.
Here's why
Rick
www.rickjohnsoncabs.com
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Bill A. Moore
From:
Silver City, New Mexico, USA
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Posted 17 Oct 2008 7:22 am
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| Ken, know I'm dating myself, but I have a tool that was made to twist wires together, pliers, with a twisted shaft in the center, give it a pull, and the plier rotates, haven't seen another in years. Thank you too Rick for the pic's, I hope to have as nice a lead dress as you pros, and hopefully no hum. Jim, I learned about ground loops the hard way, I sold some EV speakers and amps to a "contractor" to install in a skating rink. After the "contractor" left, the owner kept calling me about "that noisey d*** EV system, he's going to return them and buy JBL and crown". I went over and checked tho whole system, and found that a mic drop,(about 100' from the board), had the shield wire connected, I cut and taped the shield at the mic end, no more hum. I spent most of a day with my fluke to find that one connection! Thanks again for the great info, Bill. |
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John Billings
From:
Ohio, USA
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Posted 17 Oct 2008 2:41 pm
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| If you like that old-style push back wire, keep your eye out at Goodwill for an old Hammond. The lesser models no one wants are dirt cheap. They have about a mile of that wire in them, in a bunch of different colors. They frequently have great Jensen speakers, and Amperex EL-84s too. If you get one that has the separate reverb amp, you can build a Doc Z clone. The original Carmen Ghias were actually built with the Hammond reverb amp chassis. Doc added a tone stack, pre amp and controls to the original Hammond parts. |
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Stephen Gambrell
From:
Over there
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Posted 18 Oct 2008 12:00 am
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| Ken, you know I love ya, man, so why you wanna torture a broke-down, still unemployed fat old man like me? |
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Ken Fox
From:
Nashville GA USA
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Posted 18 Oct 2008 11:29 am
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Call it a weakness, Steve! I just love to see you cry.
I can't wait to get the cab and put it all together. Got the amp done and tested today, sounds awesome!
Mallory 150 alert! This is from a post I did on another Forum:
After building a Vibrolux clone with all Mallory 150 caps I decided to investigate this outside foil thing a little further. In good faith I had believed that the outside foil was to the left as you read the writing on the cap. Wrong!!!! I found one of the .1/600 volt caps that had the outside foil on the right. That proves you got to check them all.
Well as it goes, I had every cap but one in backwards anyway!! Changed them all around and a great improvement in tone and perceivable headroom as well.
One never stops learning.
By the way, the amp sounds awesome!!!
Aiken's article is here on the caps:
http://www.aikenamps.com/OutsideFoil.htm |
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Stephen Gambrell
From:
Over there
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Posted 18 Oct 2008 10:57 pm
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| Rick, that's a neat-looking chassis-holding jig you've got there. |
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Ken Fox
From:
Nashville GA USA
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Posted 19 Oct 2008 5:00 am
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Rick, I like that a lot, too! Mine is set for a Twin only.
Want to make another one?? Let me know how much and I will send you a PayPal on that!!
I think you have a nice item for marketing there, Rick. |
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Jim Sliff
From:
Lawndale California, USA
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Posted 19 Oct 2008 5:55 am
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Ken - I've been using the same drill-twist method for years as well. I pity the poor guys who try to twist 'em by hand! I think in my Ampeg "project" (aka "resurrection") I may go with a DC filament supply. I know enough about it, just never have done one since most of the amps I work on are not ones I'd drill holes in.
Rick, that jig is great! I use something slightly more low-tech - a pair of glued-together, stacked 2x4 assemblies with finishing nails for the chassis holes (which I can remove and reposition depending on the amp). I had them sitting on another board with finishing nails at the edges so they wouldn't move, but (being stacked on the flat side - I think they're made of 4 2x4 pieces...maybe 3...I'd have to go in the garage to check) the "platforms" are so stable I don't even bother with the base anymore. And the two "stacks" take up very little room when I'm working on something other than an amp.
That's interesting about the foil caps. Another reason I wish I hadn't junked my old 'scope a few years ago. That's one piece of equipment I should have kept when I stopped actively doing amp service (just not enough time for that and my day-job AND gigs AND practice!). I might have to try to find a cheap one at the next electronics swap meet.
_________________
No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Ken Fox
From:
Nashville GA USA
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Posted 19 Oct 2008 6:01 am
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| I still have my old single channel B&K 10MHz. If I can find a nice dual trace I would grab it in a heartbeat! |
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Bill A. Moore
From:
Silver City, New Mexico, USA
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Posted 19 Oct 2008 12:06 pm Once again, I learn something on the Forum!
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| Ken, thanks for the info on the Mallory 150's, I haven't looked yet, but I didn't know there was a difference, and paid no attention when installing them. Jim, Is there too much voltage increase, to just install one of those square full wave bridge rectifiers in the A/C circuit? Thanks again for the info, Bill |
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Ken Fox
From:
Nashville GA USA
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Posted 19 Oct 2008 5:46 pm
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| Some of the Marshall amps use BR106 and BR110 (6 amp amp and 10 amp) bridge rectifiers in the heater circuit for preamp tubes. Just a thought! |
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Rick Johnson
From:
Wheelwright, Ky USA
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Posted 20 Oct 2008 4:19 am
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Ken
Here is another pic of my amp caddy.
I will adjust from a small Tremolux
to Twin Reverb. It allows me to keep
the tubes installed and still work
on the chassis.
Its adjustable and works pretty
well.
Rick
www.rickjohnsoncabs.com
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Jim Sliff
From:
Lawndale California, USA
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Posted 20 Oct 2008 5:13 am
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A bridge rectifier would work - I just have all the info on hand about DC filament supply using a small transformer and thought it'd be interesting to see how much difference it makes.
_________________
No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Ned McIntosh
From:
New South Wales, Australia
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Posted 22 Oct 2008 6:07 pm
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I think Bill Moir is referring to safety-wire twisting pliers, you can get these in several sizes from any aircraft tooling supplier (Brown, Avery, Wicks, Aircraft Spruce & Specialty etc). Ought to work a treat for filament supply wires.
_________________
The steel guitar is a hard mistress. She will obsess you, bemuse and bewitch you. She will dash your hopes on what seems to be whim, only to tease you into renewing the relationship once more so she can do it to you all over again...and yet, if you somehow manage to touch her in that certain magic way, she will yield up a sound which has so much soul, raw emotion and heartfelt depth to it that she will pierce you to the very core of your being. |
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