Phase Linear 2000 recap questions

[J!m]

I’m less of one. He designed op amps for a living!

 

[George S.]

No one wants a turn ON or turn OFF “thump”. You may want to install a 4.7M Ohm 1/4W 1% resistor, or something close to that, from those larger value Capacitors to Ground to ensure they bleed off properly when powered down.

Making a note to get some with my next order and give it a try. Thanks Mark L.

 

[MarkWComer]

No one wants a turn ON or turn OFF “thump”. You may want to install a 4.7M Ohm 1/4W 1% resistor, or something close to that, from those larger value Capacitors to Ground to ensure they bleed off properly when powered down.

In your chain of components, ALWAYS power the amp head up LAST, and power it down first…

 

[wattsabundant]

Power supply could be improved with 7812 & 7912 (+/- 12V) regulators. If the raw DC voltage with about 110 VAC input is above 15 volts, the 12's will work ok. I used these in a TO92 package on my 3300 preamp. Built them on perfboard a little bit larger than a postage stamp. Ebay now has PCBs available.

 

[MarkWComer]

Of course, I’ve been chronicling this process for the benefit of the “kitchen technicians” who attempt things at home with little or no previous training:

https://m.youtube.com/playlist?list=PLYiWdKX5NXBLJ1zbRx3icecaOi-uVuVyX

 

[J!m]

I am a kitchen technician.

Washing dishes every night.

 

[MarkWComer]

Finished the preamp rebuild today:

 

[George S.]

Good video Mark.
He should be very happy with the preamp.
That resistor across the power switch has caused many to say the model is junk.
Thank Joe for solving that issue long ago.
I've got the output cap bleed resistors that Mark L. recommended in hand. Will give them a try once I have time to get back to the preamps.

 

[MarkWComer]

Plugged her into the big amp, sings quite nicely!

 

[mlucitt]

Glad you are happy with the modifications, Mark.
The "Book of Hints and Fixes". I like that!

 

[MarkWComer]

Curious- how much do techs make these days?
Looking for a basis on other repairs, my nephew is supposed to be bringing a Teac X10R for me to check out.

 

[Gepetto]

Curious- how much do techs make these days?
Looking for a basis on other repairs, my nephew is supposed to be bringing a Teac X10R for me to check out.

As much as you can Mark