Great American Sound Thalia 1 Service Info

[gasgeek]

Here is some information regarding the GAS Thalia 1. Hope it helps someone out.

As always, send me a pm if you need something.

 

[Noise2000]

Many thanks!

 

[llwhtt]

Many thanks from me too! I've owned my Thalia for 20 years or so and have NEVER been able to find any info other than the schematic and interconnect diagram. Thank you GASGEEK. Keep it coming!!!!!

Craig

 

[tballinger]

@gasgeek Do you happen to have a service note for the Thalia that deals with modifying the sensitivity of the volume knob? My volume knob is excessively loud at 2-3 clicks of the wheel, and I'm hoping there's a way to adjust it so that I can use the volume knob more fully.

 

[rayma]

Have you tried using the -15dB mute switch? That may be about right as-is.

If not, you can change the mute switch 12k resistors to a different value,
smaller for more attenuation.

 

[gasgeek]

There isn't a mod for the volume control. Maybe you just have excessive input level?
I've never had or heard of an issue like that before.

 

[rayma]

It's an old preamp with high line gain, and he's probably using a 2V source, so no wonder.
Just use the -15dB mute switch.

 

[llwhtt]

I always use the mute switch on my Thalia and Thoebe for that reason, I sure wish the Thaedra had a mute switch. You could play with the feedback loop in the line amp in all of these preamps but the tone controls are in the feedback loop so not so easy.

Craig

 

[rayma]

Add a resistor to ground from each volume control wiper. Try around 10% of the pot resistance value to start.
Go smaller if it's still too loud. Don't mess with the nfb loop.

 

[tballinger]

I’ll try the mute switch now. Never even considered that! My soldering skills are a bit uneven, so I may take it in for service to make any component adjustments.