Tube Amp Archive

Hi Bob
It's one of Dana Hall's VVR boards, cathode bias up to 50watts output, it's a 0.5 watt pot, I've never had a problem with one.

Regards Maxfac

Hi Just thought I would post an update. I decided to go back to a single master volume, I missed the tone shaping capabilities of the OD level (Ratio). I changed the mid cap values to 0.0022uf and 390pf which gave a more useful boost. I also added a passive series fx loop which worked as long as the...

Hi Colossal The tone is very good now (IMHO) I'm especially liking it with my Strat it seems in OD to have just enough of that compressed quality that I hear in the Dumblesque clips others have posted. With my P90 loaded Les Paul smoothness goes a bit but backing off the vol on the guitar gets seems...

Oops forgot to mention I also added some NFB to OD2 which also helped to tighten the bottom end up as well.

Andy

Hi Colossal Thanks for your suggestions, I added the 220k's on the channel switch before the Master Vols and it's got rid of all the harsh distortion I was getting, balance between the clean and OD channel is easily achieved though the OD channel is louder for the same master volume setting but ther...

Hi Wicker No clips as yet, hoping to get around to it soon. I've got a number of guitars (Tele, Strat, LP P90' s and HB, ES335 ) I can get my hands on if I ask nicely, so I'll can post a good variety, anything you'd particularly like to hear ? Cleans and/or OD? I can't say much for the standard of m...

Hi Colossal Thanks for your efforts to help me with this. I've put the 250kA Masters in this afternoon and it's made such a positive difference I'll try adding the other 220k resistors when I can figure out where to put them. The amp has less volume though, it was very loud before, quite a bit loude...

Hi Colossal I've tried Mat's 280k grid stopper to the EL84 and it seemed to take off the high frequencies a bit but not much effect otherwise. I'll try swapping out the masters for 250k pots and report back. What would the extra 220k resistor in front of the pots do ? As for the voltages on the EL84...

Hi Colossal The separate 1MA Masters seem to give a good balance between the channels, the OD side is still louder of course but OD gain on 5 and OD Master on 5 gives a slight boost compared to the clean gain on 5 and Clean Master on 7.One thing I have noticed is that the EL84 seems to be slammed to...

+1 for Dave Hunter's Guitar Amp Handbook First amp I built was a scratchbuilt Two Stroke amp that he outlines at the back. It's basically a Tweed Princeton with overspecced PT and OT so that can it take bigger output tubes. I learnt a lot on this one. It's now a THD Univalve thing (sort of similar b...

Hi I thought I would post an update on smoothing out the od on my SE ODS. First off I discovered a dodgy bass pot and when changing it realised I had changed the mid pot to a 250k from a 100k, however I hadn't changed the 0.047 to a 0.01 cap. The tonestack now worked better, much more bass and more ...

What effect on the EL84 grid reference will putting the ratio trimmer after the master. I apologize, but I don't understand the question? With respect, 10thtx[/quote] Hi, I'm not sure I do either, :? :oops: but here goes. Because I've got separate master vols for each channel (I did this to balance...

With the experiments I've done with SE and low watt D-inspired amps, I'd be tempted to try this to get a smoother OD tone. BTW, nice having a SCH file to use! Thanks. With respect, 10thtx Thanks for all your suggestions. I wonder if you could explain some of your ideas before I work my way through ...

Hi Horacio Sorry you couldn't open the file I've attached a GIF hope this is ok. I used both the PT and OT from the BH5, I found the PT specs on the net (can't remember where) and satisfied myself that it would be ok,experience seems to bear this out, no overheating or bangs or flashes even after an...

Hi all, great forum, I've been around awhile but not posted much as yet. I mainly play at home and smaller jams so I'm interested in getting some D style tones at low volumes. To this end I have built a D-lite style pre with a VVR equipped SE EL84 power amp on a old Blackheart BH5 chassis, borrowing...