Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TIMBO on September 20, 2010, 12:24:41 am
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HI guy's, I've had outstanding success with my TOS build. I've posted the voltages because i think the voltages on the power tubes are a bit high??? although it does sound outstanding :grin:It does have a bit of white noise and a small hum when turned to max. The OD Drive pot is a little scratchy but not bad. Please feel free to add as your on going help is most grateful.Thanks
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Very NICE!
what size chassis did you build that in?
I'm getting a bit of white noise too with everything dimed, hard to get rid of in an amp that has 4 gain stages.
Super Sanitary layout.
And how bout that OD? Soooo many different voicings on one knob!
I got to hear my TOS tonight with an acoustic fitted with a Fishman. that clean channel is so clear!
Ray
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Whoa!
did you use copper trace to run your busses on your board?
Neato!
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Very nice. How'd you do that board?
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VERY nice! Looks great! Voltages are OK from my perspective.
If you can, post some soundclips.
With respect, Tubenit
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The OD Drive pot is a little scratchy
Possible that the coupling cap after V2B (.0068 leading into Drive pot) is leaky....DC on the pot(?)
Congrats on the great build!
Sound clips would be good, too! :wink:
Geezer
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Great layout and super neat lead dress!
Those copper strips look fantastic for grounding. Not so sure about using them for high DC voltage though. I try to keep the power rail insulated wherever possible. Please forgive me for knitpicking - it's just that your build looks so damn good!
Filter caps close to their respective circuits always a good idea IMHO.
There sure are a LOT of pots in that build.
Cheers,
Chip
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The chassis looks fantastic.....nice work indeed. You have more patience than I.
What are your plans for things like face-plates, cabinet/head and speakers?
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Thanks for the feedback guy's,The head cab is underway , Speakers are two 50w Mods. The chassis is 1mm thick steel 9"x20"x3.5"As for the boards i just use copper clad fibreglass board and etching solution.I keep the copper side up as it makes it easier to remove components.I am thinking of using turret lugs with the copper traces on the underside of the board for my next build.I thought it a good idea to put the FATTNESS pot and the OD TRIM on the front just to make it easy to get to. I'm looking to have some face plates made of 2mm perpex (thanks to the forum member who gave me that idea) Thanks to all :wink:
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Nice build!! I really like the board idea, do you mind if I use this idea on my next build? That is to put the traces on the bottom and turrets. I was thinking I would solder the turrets in after staking them for a good connection. Only problem I see is the turrets that Hoffman sells will not fit the thinner circuit boards but I have plenty of the shorter ones. Southern California is nice there are many places to pick stuff up from once you get to looking for it.
Tony
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Hi Tony,Go for it !! The idea to have the traces on top was to make it easy to change parts for tweaking. I too was thinking of flipping the board as well to have the traces on the under side.( one of the members commented that components were crossing HV traces may not be a good idea) I've used a 2mm thick board which i can get local. I have not used turrets yet, but i can see them being a good idea. I like my boards to be regimental (two holes per component or two turrets per component) this could add a lot of extra work. My idea was just to solder the lugs only . Just to add ,i etch the boards myself ( not hard ) Thanks
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What did you mask the board with?
Tony
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I'M not sure what you mean .To make the traces i used a blank PCB (copper one side 2mm thick fibreglass board ) i make a layout and drill the holes for the components and use a permanent marker to join the dots :wink: Five minutes in a etching bath which removes only the exposed copper, clean the traces with turps and all is done.I've added a photo of the turret lugs i got from my local parts suppliers. I though they were good, they stand off the board about 3/8" with a hole through the centre but have a notch at the top. I would think it's to be able to lay the leads into rather than bend the leads into the hole (but if anyone has another idea as i have never used then before). Thanks
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The permanent Marker is what I was after. I didn't know if you used tape or maybe did a mask on a laser printer. It seems simple enough a circuit that a marker would be the easiest way.
Tony
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HI Guys, Been doing some tweaking to the TOS ( although as it is there is not much room to move) but anyway i remember reading somewhere that Geeza thought of adding larger caps the 5879 cathode, 10uf & 25uf. I put them on a rotary switch to make switching easier.This added a bit more grunt. Should the resistors change with the cap change?? Also, changing the cap/resistor on V2b would this be of any added value, if so any ideas to what they would be. Thanks again as it is a great amp. It works well with a Les Paul standard, Standard fender strat, Les Paul Jr (single P90) and Cort acoustic (Fishman pickup). I cant post any sound clips as i am not up to that standard of playing (spending to much time building amps thanks to you guys :rolleyes: :grin: :laugh: :laugh: :laugh: :laugh: