Laney AOR 30. Want to add a choke. Thoughts?

[nholden59]

Hey Folks:
New around here. I'm taking delivery of a late-'80s Laney AOR series 30 watter. 2x 6v6s. I want to add a choke to it since I seem to remember the verdict on these is the supply could use some smoothing out. I'm also chanking the 1n4007s to Ixys Hex FREDs.
I have the schematic. I need some help with where in the circuit to wire in the choke. I'm a bit of a newbie to electronics, but I'm pretty handy with a drill and soldering iron.
Any help appreciated!

[TransLucid]

Replace R67 with the choke.

[Gtr_tech]

I'd add screen resistors on the output tubes as well.

[nholden59]

WOW. Thanks guys. Much appreciated. R67. I'll look at the schematic; shouldn't be difficult, other than frinding the best place to drill the mounting holes. I'll look at adding screen resistors too.

[J M Fahey]

Choke and resistors are fine and will improve the amp.
I'd leave the old faithful 1N4007 though ... doubt that Laney uses an SMPS , and at 60 Hz, 4007 are better.

[J M Fahey]

Loved the salesman's babble used to push HexFreds into customer's amps:
cut and paste from "Pro Tube Store":

How do they sound?

Compared to silicon diodes, FREDs have a full and airy sound. The bass is tightened up, and the harsh edge in the mids and highs almost disappears. Details in the music start to come out with greater clarity than ever before. FREDs sound as close to a tube rectifier as one can get, while not requiring additional power to run a filament or heater.

Most modern audio equipment including amps, preamps, CD players, etc will be improved significantly by installing FREDs. Good vintage hi-fi candidates for upgrading to FREDs include: Fisher 400, 500, 800 receivers, Fisher tube integrated amps with silicon rectifiers, EICO HF-87 and HF-89, Harman-Kardon Citation II and V, H. H. Scott 340B receivers, Sherwood integrated amps and receivers, McIntosh amplifiers, preamps and tuners, Marantz amplifiers and preamps, etc. Heck, they will even make most of your solid-state gear sound much better.

Note: FREDS also sound great in all guitar amps, tube or solid state!!!

VTV Pro-Shop carries the high quality German manufactured IXYS FREDs that come in 600 @ 8 amps and 1200 @ 11 amp ratings. Typically, diode peak-inverse-voltage ratings should be at least twice the DC supply voltage, because the rectifiers have to handle both positive and negative AC voltage peaks. Example: if the circuit will produce an operating voltage of 250 volts DC, it would require a FRED with a minimum of 500 volts rating. Be conservative, as there is the added possibility of occasional line-voltage spikes.

You can use IXYS FREDs in Bias, B+ and Filament supplies. Even though they are more expensive than ten-cent 1N4007 diodes, installing FREDs in your power supply can improve the sound of your system to a greater degree than exotic cables or most other tweaks. You will hear detail and depth in your music that will astound you!

After reading this, I'd say: RUN !!!!!!

[tedmich]

SiC diodes sound much fuller, while your wallet is definitely airyer!

Cree C4D02120A 1200v 2A $2.88

[Alex R]

Freds have a full and airy sound they taste great too, dip em in your beer