Scott Type 130 Phasing Problems

[BrianC7927]

Hi,

My current set up follows

Pioneer SA-9100 integrated amp
Scott Type 130 Preamp
Technics sl-1700 turntable
Energy es-12xl sub
Pioneer hpm-60 speakers

I have been having phase shifting issues that I am stumped on. My album listen starts fine typically, sounding good. Then, after an unpredictable amount of time, it goes out of phase losing bass and some sound from right channel. When i run the system without the Scott pre amp, I do not seem to have the issue. If use the integrated pre amp on the Pioneer this does not happen. When it shifts out of phase, the phase switch on the Scott works, but does not put it into proper phase sonce it is not 0/180 degrees, its in between.

The big problem is, if I get up, flick the phase switch, or turn the system off and on, I can get it to shift back to 0 phase sometimes, but it's unpredictable. It will stay, or go out phase or back in again.

I have had the Scott looked at 2x by expert technicians, they can't find anything wrong with the Scott.

I've checked all wires, speaker cables, speakers, and had the amp looked at too. Everything is perfect and I can't figure it out.

I did try adjusting the sub to see if thst was the issues but it happened when the sub is off too.

Any help is appreciated
Thanks
Brian

 

[century tek]

Sounds like it needs the old fashioned deox treatment first of all pots and switches. When this happens, wiggle the tape monitor, loudness, and tone defeat (if it has one).

Don't know why you need the 130 preamp?

 

[Selmerdave]

If it seems to be at all related to the phase switch I'd just replace that. It's one of the few parts that is standard even today, I would think a standard slide switch will fit, just check the pin arrangement (SPDT etc).

 

[gadget73]

the only thing that comes to mind as a possible cause is that phase reverse switch or maybe some issue in the controls. If a control wiper was losing contact you might get some funky behavior. Also possible if this has a selectable EQ on the phono side, some issue with the switch there could give you some trouble.

either way, controls cleaning sounds like a good place to start. Maybe re-seat the tubes as well.

 

[BrianC7927]

Sounds like it needs the old fashioned deox treatment first of all pots and switches. When this happens, wiggle the tape monitor, loudness, and tone defeat (if it has one).

Don't know why you need the 130 preamp?

Thx. The 130 preamp with the pioneer sounds better than the pioneers built in preamp. The tube and solid state combination imo is much smoother and warmer than pure solid state.

 

[BrianC7927]

If it seems to be at all related to the phase switch I'd just replace that. It's one of the few parts that is standard even today, I would think a standard slide switch will fit, just check the pin arrangement (SPDT etc).

thanks I will give it a look, appreciate it

 

[BrianC7927]

the only thing that comes to mind as a possible cause is that phase reverse switch or maybe some issue in the controls. If a control wiper was losing contact you might get some funky behavior. Also possible if this has a selectable EQ on the phono side, some issue with the switch there could give you some trouble.

either way, controls cleaning sounds like a good place to start. Maybe re-seat the tubes as well.

Good feedback, thank you I appreciate it.

 

[cademan]

The 130 preamp with the pioneer sounds better than the pioneers built in preamp. The tube and solid state combination imo is much smoother and warmer than pure solid state.

There is nothing wrong in using a tube preamp with solid state amp and vice versa. To each his own. I use just the opposite of yours. I use a solid state preamp with an all tube amplified system. I just found a good combo that works for me but in the end, it is still true tube sound:
Tube>output transformer>to speaker.

Solid state at the speaker connections will still be solid state sound:
Sand>capacitor coupled(certain designs)>to speaker.

 

[Dadbar]

Scott used really crappy slide switches in that era. Bypass as many of them as you can and replace the critical ones.

 

[BrianC7927]

Thanks for the replies all. So far it seems the right channel RCA out connection from the Scott 130 is bad/corroded. I cleaned and fit the plug better to it, has improved sound. May be the phase switch as well, will continue to test.

Your assistance helped me hone in on the issue. Appreciate it.