kevin gilmore

i need to know what the version numbers are for the boards you have. way to many, and no idea which boards were the first GB. I switched to the motorola parts because in general the toshiba parts are not available, and they are not pin compatible.

happy birthday tyll

http://gilmore.chem.northwestern.edu/kgdynalobalssproduction.pdf r38 and r39 on my version its 255 ohms i think 200 ohms should be about right for 20V

on +-15V power supplies it will do about 30vpp balanced on +/-20v power supplies it will do about 40vpp balanced on +/-15v power supplies its 200ma per channel. would need to adjust the bias resistors to reduce the current for 20v. works out to at least 2.5 watts rms pure class A into 50 ohms

http://gilmore.chem.northwestern.edu/ssdynalobal2.jpg loving it with he6

you are missing the most important, and least important amplifiers!

Fine, I will squeeze the expensive 4.7uf film caps in... done

Those pictures are fakes and dalbani knows it. Don't ever buy from them. 2sa1967 real things have the cutouts at the bottom of the transistors just like the 2sa1967. Only difference is that the 2sa1967 has an exposed tab and the 2sa1968 has plastic tab. I have some real ones, which I may dig out later and take pictures of.

this is the production version http://gilmore.chem.northwestern.edu/ssdynalobal.jpg

only one set of input devices. this is unbalanced/balanced in, balanced out

if you are going to buy a bunch of transistors the dy294 from ebay is what you need and cheap

which chassis is that?

very nice

yep 10:1 or 100:1 with an impedance of R1 = 500K or more

second row, second and 4th are pictures of the real item if it does not have the slits in the plastic by the pins it is not real

you need a 120pf dummy load, and a minimum of a 10x high impedance attenuator otherwise one accident and you blow the crap out of the AP

so remember ZENITH... The quality goes in before the name goes on. (ok you have to be at least my age to remember this) (and between 1965 and about 1980 compared to everything else it was actually true) well cavalli is the reverse of that The quality never goes in, but sure is a pretty box It would have been so much easier to add terminal blocks on one end of each board

that looks good to me, but I would never attempt to build something that small

so alex released his latest $4700 piece of crud http://cavalliaudio.com/index.php?p=morestuff&stuffId=13 notice the LDR volume attenuator. notice the distortion of the LDR http://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-new-passive-preamp-134.html#post1520243 notice the pile of soldered in jumpers tying the 3 boards together making it absolutely impossible to ever fix the thing. at least the load for the tubes/mosfet is now more rational on a single heatsink kind of feel sorry for all those llmk1 and llmk2 owners whose amps are now worth nothing...

its been posted already. since rkv is not a sponsor there, they probably don't give a shit. clone board now available, usual place. if you read the French forum, the manufacturer has already decided that 1:5 transformers cause all sorts of grief, and now they are making 1:14 and 1:20 transformers. Between a rock and a hard place they are. The amp may be just ok, and only for high impedance dynamic headphones. The transformer box is a clusterfuck for electrostatics.

because if you clip the output like you would do with testing with scope and signal generator, the top fets blow due to reverse bias on the gate. mosfets on the output are a bad idea, but some people want them.

2sa1831 is only an 800V part. So you would have to cut the power supply voltages down to +/-400

very nice job. you are ready to do the T2.

so I did some playing around with a lundahl ll9202 transformer. setup to drive electrostatics. Using all the lundahl specifications, and what I get on the scope looks almost identical to this simulation. top graph is frequency and phase 20hz to 20khz, the bottom graph is 1khz square wave. Using a full synthesis of the rkv amplifer. synthesis by the way of the rkv indicates a real impedance of about 800 ohms. http://gilmore.chem.northwestern.edu/rkv.jpg while not exactly the same transformers that are in the verto, my guess is that the verto looks like this or worse. this is not a minor aberration to the frequency response. This is a complete fucking of everything. The graphs on the rkv website as well as everything out of eric65's mouth seem to be a complete fabrication.

half of the differential gain comes at the output stage. there is a offset and balance control. This takes care of everything. Really!