5 posters
new quad cap, on to the driver now,
dmagazz- Posts : 147
Join date : 2018-06-20
Age : 56
Location : new fairf, ct
- Post n°1
new quad cap, on to the driver now,
audiobill- Posts : 425
Join date : 2014-03-13
Location : Albany, NY
You should just replace the whole driver board with Roy's.....
dmagazz- Posts : 147
Join date : 2018-06-20
Age : 56
Location : new fairf, ct
Dave_in_Va- Posts : 446
Join date : 2013-04-02
Location : Mid. VA
dmagazz- Posts : 147
Join date : 2018-06-20
Age : 56
Location : new fairf, ct
Dave_in Va
thanks man, is seen that. been all over that page with a monster wish list!.
i just got done with the driver caps too. couldnt wait
i will possibly get that board eventually, but for now i just want to refresh mine
top and bottom of the board
i went and resoldered some sketchy looking points too.
WLT- Posts : 189
Join date : 2013-07-13
Location : Rochester NY
Nice job. It looks great. You can always replace the board but you have your board looking good for now. I did the same but also went thru the resistors to check their values. Many of the old carbon comps will drift. And not match channel to channel either. I decided to replace several of them and now both sides have similar operating voltages. They sound great as well. No need for a new board for me.
dmagazz- Posts : 147
Join date : 2018-06-20
Age : 56
Location : new fairf, ct
thanks.
i figure the same. knowing what heat may do to the solder traces on threse old boards kept me from removing ends of resistors to check them.and its possible the old carbon might change value with the heat or the movement of the lead in the bond as well. so. im leaving them to continue their job.
i figure the same. knowing what heat may do to the solder traces on threse old boards kept me from removing ends of resistors to check them.and its possible the old carbon might change value with the heat or the movement of the lead in the bond as well. so. im leaving them to continue their job.
WLT- Posts : 189
Join date : 2013-07-13
Location : Rochester NY
For the most part I do not un-solder them. Obviously several will have incorrect readings this way. You can find the ones on the stock schematic that are in parallel with others that will give erroneous readings. The rest will test fairly well. Most of the resistors have a high value so they actually read as if they were open air tested. In particular the voltage amplifier plate and screen grid resistors and the phase splitter plate/cathode resistors. They all should be matched or very close to the schematic value.
The overall feedback resistor and the voltage amplifier cathode resistors will influence each other. If each channel measures close to each other I let them go. If they are off I un-solder them for further testing.
The overall feedback resistor and the voltage amplifier cathode resistors will influence each other. If each channel measures close to each other I let them go. If they are off I un-solder them for further testing.
dmagazz- Posts : 147
Join date : 2018-06-20
Age : 56
Location : new fairf, ct
thanks for the insight. maybe ill compare them later today. right now.. im enjoying them
ttownscott- Posts : 40
Join date : 2018-07-31
Age : 60
Location : Tacoma, WA
- Post n°10
Re: new quad cap, on to the driver now,
Thanks for your postings. I'm right behind you in my amp rebuild.
dmagazz- Posts : 147
Join date : 2018-06-20
Age : 56
Location : new fairf, ct
- Post n°11
Re: new quad cap, on to the driver now,
enjoy. i think if i was to do anything different id would have used sprague caps(they are a little bigger). but it worked out sounding very nice! im happy with it. im gonna be working on an extension that mounts to the back pretty soon. it adds 4 lugs and a toggle to enable a center speaker to be used.just havent settled on if i want to use old school screw terminals(as the mod would have been made in the 60's) or newer style more robust connectors.
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» The making of the driver board covers for the VTA driver boards - video
» High Voltage Quad Cap and Mk3s To Replace or Not...
» voltage reading results are in, changed selenium,changed quad cap and driver board caps .
» Low bias voltage throughout- is it the quad cap? [Update: It was the quad cap.]
» The making of the driver board covers for the VTA driver boards - video
» High Voltage Quad Cap and Mk3s To Replace or Not...