400 comes home, FULL CIRCLE......................

I'm gonna call this one DONE!!!!! EDIT: As of 26APR19 IT"S DONE. Absolutely NO Hiccups, FM is fairly Decent for the area, Stereo Separation needs some work tho (MPX Alignment). Now on to getting the standalone 800c back in line. I havent run it in 3-4 years so on the variac @ 60 V and a 3way bulb on the DBT, it goes tomorrow morning Bulb is a 50-100-150W.

Found HUM in FM and AM on the C.E. VII today. As I didn't do anything to the Tuner/preamp. I'll recap it including the CAN. Should take an hour or two. Not much to lytics and films on this.
 
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So when Dave came up with the 400/500b/800b/500c/800c UPGRADES mod, I had the 800c on the bench for a freshening. Got it upgraded on the P.I.'s and I can run Russian Tubes in the P.I. (Tung-Sols or EH's), So I figured on doing the 400 too.
See this thread https://audiokarma.org/forums/index.php?threads/400-phase-inverter-mod-install-project.866989/

Did a couple more items that needed attention.
1.) Installed the PHONO TUBE isolation Grommets.
2.) Re-Located the IBAM so the P.I. Upgrade would fit in.
3.) Added some Black weatherstripping to the Front Plate to keep the light in.
4.) Printed out the Mod drawing for the P.I. and pasted it in the 400's manual for future reference. Also the Adjustment procedure.

Still need to see K.C. about aligning it. He's got all the stuff we need for it and he's a HAM (ARRL TYPE) that works on his own gear. I've got it close BUT close only counts in Horseshoes, Hand Grenades and Claymores! Button the Bottom up, and put it back in it's case.

Now on to a H-K TA-260 Festival II with 7355's in it. See if I can get that beast running again.
Under the Kilt Shot.
100_5478.JPG

Topsides. Note the Phase Inverter Pots are now on top. Existing interferences, lack of real space underneath, and the size of the pots precluded an even installation. But they work fine.
100_5479.JPG
 
Late update. I took it down to Dave's last summer and he did a FANTASTIC Alignment on it. Ran it about 3 months and rotated the other 400 in on the basement receiver unit. Now have the Sui 1000A hooked up.
 
larryderouin said:
Late update. I took it down to Dave's last summer and he did a FANTASTIC Alignment on it. Ran it about 3 months and rotated the other 400 in on the basement receiver unit. Now have the Sui 1000A hooked up.
Click to expand...
Hi Larry, good job in stuffin' the p.i. pots in there!
I've had a Sui 1000a in the reserve stash, a later model with the 4 bias pots, ever since the late 70s when I acquired it while stationed in n.w. bumfuque, turkiye. Had loaned it to a late uncle way long ago, he had a fire at his house at the time he had it. He took my advice on running it minus the steel case due to its inherent room-heating ability, only to have the case disappear. I long ago got it back, it's been dormant since, but for a couple ops checks over the years. Dumbski me had pulled the original Toshiba 7591s for whatever reason, rubber-banded them together for "safe-keeping", & much later found them with one envelope cracked, likely due to excessive "togetherness", probably too-tight rubber band. Superfluous factage, yes I'm guilty. Back to my question: where did Sansui put the serial numbers on these things? Last time I had it off the storage shelf, I couldn't find it anywhere. I suspect they may have put it on the case somewhere, which would've been rather dumb.
Keep up the good work, stay healthy & entertaining! Jerry
 
Earlier units had it rubber stamped near the AM antenna mount. Later units had a paper sticker right around the inner output transformer or in front of the 7591's between that trans and the Power trans.

If you're gonna rehab it, get a quad of the Tung-Sol 7591's vs. the EH's. Granted the EH's will fit, but they are really close together and those areas between the trannies get hot enough to fry eggs.

Have a look at this thread about the power resistor replacement I came up with . Between the T-S, power resistors replacement, and some judicious use of HVAC 4" Aluminum tape on the sides of the transformers, along with bumping the bias down to 70%, it runs pretty cool with the top ON. overall the unit is consistantly warm, but it now NOT a spot heater. https://audiokarma.org/forums/index.php?threads/1000a-power-resistors.536768/ AND the IBAM or IBBA developed for the FISHER's actually works very well on the 1000A without changing any parts on the IBAM/IBBA. It replaces the open pots and the 10K resistor on each sector. converted mine from a 2 pot to IBAM back in 2011. I'm really tempted to revamp it to an IBBA. And the T-S's are holding without changes to bias in it.
 
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