Quicksilver Audio Tube Preamp Restoration (Part 2.5) Phono, Vinyl, Audiophile DIY!

Hello Alexander , benide the transformer is a big yellow foil cap..............next to the left leas of the cap runs the twisted yellow wires for the heater supply............this draws big curent and genrates an important electroagnetic field arround the wiring ..............you can push the cap away to the left ( and expecialy the right lead ) as far away as possible from the yellow twisted wiring and the transformer ...
Tell us how it sounds ..............after some run in ..................
Those old caps were good and maybe still are because they were not abused........the rectifiers were hahaha..............
An old school advice....................NEVEr do a HOT start after shut down..............allways wait before a restart until the rectifiers are cooled down....!!!

The studs go to GROUND........I had the same studs and bolt with Sikorel capacitors to mount in my Luxman SQ 507x..........besides the obsolete BG the best capacitors I ever used , today tey are obsolete also............
Max capacitance after a GZ34 is usualy lilmited to 60 µF ,..................he ( Quicksilver) did the same in his 8417 amplifier ( another great sounding amp ).............Two rectifiers per mono bloc ( GZ34 ) and followed by two 330 µF ...........

Bypassing an electrolytic capacitor has a two faces issue .............it was a great tweak decades ago and some went so foa as to bypass with multiple foil capacitors..........
But there's are some ugly hidden facts that come along with this " audiophile " practice........

The first is that by doing so and listen to the result ...........one is usualy pleased by having a better darker background ............hahaha that worked out well.
but aftezr a while you may notice a shift in tonal collors depending on the frequency , or tonal hight ...especialy on female vocals and some instruments ( strings )...............that's a dillema ............going back to the future or not ?
Secondly ..............the smaller the capcitot the faster and higher capacitor frequezncy resonance..............Well well...............what does that means .........
the capacitor shifts gradually towards its resonce point and the capacitor caractor goes over its inductive caracter .............with a dip on the resonance frequency point ......
Both capacitors have a different inductance and different resonance frequency ..........together they create a new sometimes (a bad sounding -unesxplained stress or oscillation outside the audible range ) intermediate problem .........that can harm the sound as it can intermodulate witin the audible range.........
Best is to use same capacitors in //...............so two 22 µF in // instead of one 47B µF...........or two foils " tête beche " or two non inductive caps in //

The use of quality electrolytics is allways a better idea......the right one for the right job...and sometimes the best cap can be your worst enemy in
the wrong position.......
Have a nice day .

Nice work, just be careful not to alter any values in the RIAA EQ circuit… Takman has nice metal films too, I use them for RIAA..

Don't replace those AB CC grid stoppers with carbon film, they are carbon comp.for a reason (very low inductance).

I left all of the Nippon C C caps in my Quicksilver Full Function as they all tested a as new.

Love your mod series. I used different coupling caps in mine, but I really want to try some of those Solen film and foils!

Dan

Do you like the AMRG's more than the Z foil resistors?