So, you should get about the same power I got- about 35w/ch.
A Dyna A-470 would be effectively 8.6K into each tube, if four EL84s are used in PPP, per transformer. In my case- each transformer was about 9K, into a pair of EL84s.
that will make up most of the power difference due to the lower B+. Pentode mode will give more power on the lower B+ used by the EL84, though. The EL84 needs different tap placement percentage (IIRC, 25% as opposed to 43%?) than E元4s. If I did this- I would run the Dyna A470 transformers in pentode mode- just don't use the UL taps. But, that's been done quite well in the past- the Eico HF30 is one example. The only caveat, is that greater care may need to be taken, to avoid oscillation between the parallel output tubes. There's no reason why someone couldn't do something similar with the Dyna A-470 outputs. Slightly weird but if you have to share things, those will affect it the least. HV supplies would be split, but you'd be sharing heater and bias. The different resistance in the windings would probably make the voltages not track perfectly side to side but it may be close enough to not be a problem.īut accounting for that you should be good for a pair of channels at ~25 watts each.
You'd end up with matching voltages from B+ to ground, and the zener would take up the difference without adding a bunch of extra resistance to the circuit. Easy way would be to take the hotter of the supplies and put a zener diode at whatever that voltage difference is between the center tap and ground. With some fiddling you could probably get two supplies at close enough to the same voltage to make it an effective twin mono rig though. Its two HV supplies at different voltages, so its a little more complex to use for a stereo amp. It is a more accessible, cleaner version than the one all over the Internet now and should be very useful to anyone who does not have access to an original.Power-wise it should run a lot of things, the hitch gets into voltage distribution. It is available as PDF, bookmarked per chapter.
The scans were taken directly from original manuals of the 50s and 60s, with the exception of the diagrams for the Model E and C2-G. The diagrams/schematics/charts have been scanned in at 600dpi for maximum clarity when zooming in. The new version has been completely re-typeset, some pictures have been replaced with better versions, and some sections and some diagrams / schematics have been reintroduced from earlier manuals that were not included in version 495 from sources such as the original 1936-1944, as well as some manuals from the “pre B3” 50s. A post on the organ forum provides for the download location of a newly restored version of the Hammond Organ Service Manual for free download, painstakingly put together by Organ Forum member Joey B3.
0 kommentar(er)
