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The HH Scott 350 A MultiplexCircuitry

I've been listening some to my 350 Scott but only in mono. However my belief is that it's all stock so I'm hoping that replacing the tubes in the multiplex will clear up the noise and microphonic echo from the 6BL8. Yes, I'm getting loads of grumble and interference from the stereo selection.
An additional multiplex concern however is that the multiplex circuitry in the 350 was a compromise to the refined circuitry of the 310 E. I have procured (thanks to good Audiogon friends) the repair manuals of both the 310 E and the 350 as well as both schematics and I'm hoping/wondering if my local technician will be able to improve upon the 350 multiplex circuitry by comparing it with that of the 310 E? I was told by a friend that this is possible if I were to provide the technician with the repair manuals and schematics for both tuners but I'm still somewhat doubtful.
If anyone ( Al ? ) would shed some light on this and lend a suggestion/s for me to pass along to the technician, then I'd be very grateful. By the way, I have a Telefunken E80CF (6BL8) , A balanced pair of Telefunken 12AU7's and a Telefunken 12AT7, all Amplitrex tested on hold for payment. These I'll take with the tuner and hope that he orders the best capacitors. I want to go full force with this project to the best of my abilities.
Thanks To All!
goofyfoot
goofyfoot's avatar
goofyfoot OP
1,412 posts
 
Thanks Atmasphere,
Yes, I think it will work out. I dropped of the unit today and the technician said that they'll call me after they look at it. There's about a two week turnaround but that seems reasonable. Once I get word I'll post it here.
goofyfoot's avatar
goofyfoot OP
1,412 posts
 
OK, so here is the scoop straight from the technician concerning the 350 A; 'we can't find anything wrong with it so we want to give you back your bench fee and you can pick up your tuner also.'
The tech tested the tubes and caps and said they were fine but mentioned that there was significant corrosion in the outputs. He mentioned that 1 capacitor tested low by 10% but that he didn't want to replace it. I asked if he would clean off the corrosion and then have it ready for me today so I'm planning to retrieve my tuner this afternoon. The technician did agree however to come by and listen to the tuner in my home if I were to continue experiencing the issue with the multiplex stereo option.
?????????
atmasphere's avatar
atmasphere
12,116 posts
 
Did they perform a stereo multiplex alignment?
goofyfoot's avatar
goofyfoot OP
1,412 posts
 
No Atmasphere they did not do a stereo multiplex alignment and I told them that this was what needed to be done as well as them cleaning the oxidation in the outputs.
The technicians said they had never heard of a multiplex charger but that was after they had the tuner. I gave them a copy of the service manual and it listed what to do with the multiplex without the proper equipment but they balked. In a way I'm glad they didn't touch it, they seem clueless.
So prior to driving over to the technician to get my bench fee, I called Ryan at Audio Classics and said I'd ship him the tuner within about a month from now. Ryan said that even though it's not a tuner they typically work on, that they could do the work. And yes it will cost more but they repair the Marantz 10 B and all of the MacIntosh tuners, so I have confidence in their skill level. Also, I've been a prior customer at Audio Classics so I feel comfortable with their business practices. But what a bunch of kooks these local technicians are.
atmasphere's avatar
atmasphere
12,116 posts
 
Just FWIW, we can do a stereo alignment too. FM Stereo Multiplex generators are not as common nowadays as they used to be. So it does not surprise me that a newer shop might not have that instrument on hand.
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