CARY SLP05 - tube configuration?

Hi- is this NOS rectifier a decent upgrade over the stock? Approx market value if condition is good?

Mullard (for Zenith) GZ34 5AR4 1969 UK


My SLP-05 had a problem with the left channel, but it was intermittent. Gave up for several months and put my back-up in. Came across the upgrade, which replaces 10 caps and 20 resistors and figured they’d find the problem. Sure enough, there was a resistor which had smoked. My SA-200.2 was also improved with the current inputs. Mine was an original model with noisy parts. So far so good! Can’t directly compare the sound since it was nearly a year since I heard it.

Appreciate any advice on the rectifier.

I placed a Philips miniwatt in for the rectifier and it made a good difference.  No experience with mullards.

Mullard GZ34 are consider one of the best rectifiers made and are typically considered as a substantial upgrade over the stock JJ 5AR4. I use a 1960 Mullard GZ34 "fat base" rectifier in my slp05.

NOS Mullards run between $100 - $200 depending on year, manufacturing plant, and tube source (vendor). I always suggest going with a well known trusted vendor, you pay more, but you get quality. Also, rectifiers last a long time, therefore, the initial cost amortizes nicely over the tube’s lifetime.

@stfoth my tubes are very similar to yours. RCA grey glass in 1-4 and Sylvania chrome dome GT’s with 3 hole construction in the balanced positions.

@mikey8811 
how are you running 4 grey glass in 1-4?  That would mean that you have it along the entire front row, and then on the left-most of the rear row.