Well, it's been nearly a week now.
The 800C is working well on a quad of mixed brand (3 Westinghouse 7591's and 1 Sylvania 7591 coinbase) that are pulling between 28ma and 31ma. Out of 10 these 4 are the closest I cold put together with the BIAS supply Stock. Sound is good. Pushing a pair of KLH 20's (4oHm). Kind of lacking in the Mids but I think that's the speaker. I like them a little brighter (3ways). this is with all controls centered and loudness off. Bass shy, but it's the speaker placement (1 foot from wall, 18" off floor, center of the walls, across the room from each other the only placeI have for speakers). If I putthem on the floor on tennis balls, the bass goes up but i lose what mids I have. Tone controls can adjust for this but I don't really want to do this. I may go with an equalizer eventually. I tried Scott S-10, S-15, PIONEER CS-66e's, and Sansui SP-200's. the 200's are ungodly efficient! Where everything else is set to 10:00 on volume I get the same @ 08:00 on the sui's. I may just go with them after recapping them. And raise them off the floor some. They have the mids' covered more than the S-15's. But for close up the S-15's are somewhat better than the KLH's. More Mid, but the high's aren't as bright, like they have some kind of veil on them. Maybe speaker construction.
Getting Back to the 800 operation
FM selectivity and sensitivity is OUTSTANDING! As good as or better than my sx-790/SX-1010 PIONEERS. It pulls DC Stations in with a 3-4 on a 12" piece of wire, (40 miles away.) Stations I have problems with interstation interference on other receivers is just not there on the 800C. I expected problems with it, seeing as there is a mishmash of RF tubes, but it seems to be locked on. So I'm gonna leave the tuner alone.
AM Reception is Outstanding as well. Sharp/Broad selectivity is very good. Not too many 40+ year old receivers can say that. Sound quality in AM is very good.
Phono is good to very good depending on what is connected. I originally had a DUAL 1009 with a Stanton 400V.3 and a D71EE connected. Sounded Ok, with some very slight background hum hich I couldn't get out. I then hooked up the ZERO 100, with a Shure V15-III (Jico HE) and after fiddleing with the grounding(tying the Z-100 and the 800 together and then to the Wall ground got rid of all hum) I've got a system that sounds like a BLACK HOLE now. With the 800 all the way up, there is just the barest hint of hiss at the speakers (ear 1' away). Pacing is good, separation is good, with no fatigue after 10 sides.
This thing is a joy to listen to.
On to the ZERO 100
Thanks ARKAY. Like i told Fran, I've been "lusting over one of these" for Decades (No peanut farmer jokes guys) basically since they came out. The arm actually makes sense in execution. Application of it could be better by 2000 standards but for 1970 it was'nt too bad. Someone should try and improve on it. God knows, with all the stuff they've improved on in the last 50 years they could probably do this too. But then I like old cars more than the new one's too.
The ZERO 100 took some work. Disassembled the whole thing. Good thing the SL-72B parts unit I have has a similar if not identical mechanism as i forgot a couple of items how they came out and went back. The wiring is now right. It could use some new tonearm cables, but right now they are working fine for me. The Size selector took it's time freeing up, and I had to heat the bushing on the upper mechanism (use a soldering iron). to get it freed up so i could clean it. Now most everything is cleaned and lubed, and I stole the idler from the 72B. Sending the Z-100's idler to Terry for rehab. The Tonearm works great, and has no quirks now. A slight wobble on the strobe is from the idler. but it maintains speed all day long and doesn't drift off setting like some DUAL's. There is no Inner channel distortion that I can hear, and sibilance is ZERO. DSOTM actually improved in SQ over the SL-1700 with the V15III. And all my Glenn Miller just sound so damn lifelike it's scary. I wanted to break out my Trombone from High school, and then remembered my oldest son across town has it. Thank God. I don't think my neighbors could have stood that.
Right now the KLH 20's will do until I get the SP-200's recapped next week.
I'm wondering, how would 4 KLH 20's stacked sound. hooked up like Dynaco did for the A-25's. With them @ 4oHm I'd have to hook up in Series. Which would give me 8oHms per side. I might try this and see. Other wise it's just gonna be two 8oHm units with maybe a center speaker.
Larry
:thmbsp:
and the 12K resistor on the IBAM perform the function of C92 and R122?
