That Good Old Rectifier Sound

sKiZo wrote:

Ever think about adding some extra legs to help support all those MCaps on that driver board?

These m-cap of the driver board are silver-gold in oil. I think they not need to be strengthened.

UPDATE: Earlier in this thread I had mentioned that the Philips 5R4GYS was working OK for almost a month in my ST120. Well, within the past few days I noticed the bias was not holding and I had to keep adjusting it upward until I ran out of adjustment rotation on one of the pots. I figured that's not good so I pulled it and put a WZ68 back in. With the WZ68 bias on all four output tubes is holding at 0.55 again and doing so with less turns on the adjustment pots. I gotta assume the 5R4GYS won't make the cut in this amp???

wgallupe wrote:UPDATE: Earlier in this thread I had mentioned that the Philips 5R4GYS was working OK for almost a month in my ST120. Well, within the past few days I noticed the bias was not holding and I had to keep adjusting it upward until I ran out of adjustment rotation on one of the pots. I figured that's not good so I pulled it and put a WZ68 back in. With the WZ68 bias on all four output tubes is holding at 0.55 again and doing so with less turns on the adjustment pots. I gotta assume the 5R4GYS won't make the cut in this amp???

I had similar experiences with the 5R4GYS's in my M-125s. They sure look pretty, but don't quite make the cut. Also had a reject rate of about 10 percent out of the box.

Just to refresh the memory ... yup, same thing here. So that makes at least three of us.

Eh ... don't know till ya tries I guess. It's like sticking your tongue in a light socket.

OW

We learn from our

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mistakes.

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Most of us

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Eventually anyway

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Guess that's why Kevin had such a "Deal" on them.
Assuming the pin-out's the same, they might be ok in an ST-70.

After reading all the info about it on Upscale's website, I bought two thinking I would have a backup and be all set for a few years! I'm hoping I can return the unused one

Thanks for all the good info on the Phillips 5R4GYS!!
I almost pulled the trigger on this tube from Kevin Deal/Upscale Audio a few months ago! It makes  me question Deal's business practices as far as NOS glass. Maybe he deletes negative reviews of stuff he's trying to move out!!

I think I will stick with the Weber WZ-68; no problems whatsoever after nearly nine months and several  tube changes.

I don't think its fair to blame Kevin Deal or question his business practices. Its not his fault that the ST120 puts too much demand on most GZ34 rectifiers.

I've bought tubes from Upscale Audio. They really promoted them as being the best thing since sliced bread... And... I'm happy with them, they really are great! http://www.upscaleaudio.com/cifte-12au7/

I paid a lot less then, though.

wgallupe wrote:I don't think its fair to blame Kevin Deal or question his business practices. Its not his fault that the ST120 puts too much demand on most GZ34 rectifiers.

Yah but ... Upscale does list them as "The best buy and best made 5AR4/5U4G/GZ33/GZ37".

Neither a GZ33 or GZ37 has any problem installed in an ST120 ...

I just dropped a note to Upscale:

Just so you're aware of issues using the Phillips 5R4GYS in the Latino ST120 and ST150 amps, I know of three early failures (including mine), using the Phillips tube. They'll bias up fine out of the box, but get progressively weaker, and fast, to the point where they won't provide adequate power.

You may wish to correct your website to reflect that it is NOT a good substitute for a GZ33 or GZ37 rectifier, at least for the larger Latino amps, any of which work fine with the GZ33 or GZ37 tubes.

Somebody else mentioned the published reviews on the site ... looks like 5 stars all the way!  

sKiZo wrote:

wgallupe wrote:I don't think its fair to blame Kevin Deal or question his business practices. Its not his fault that the ST120 puts too much demand on most GZ34 rectifiers.

Yah but ... Upscale does list them as "The best buy and best made 5AR4/5U4G/GZ33/GZ37".

Neither a GZ33 or GZ37 has any problem installed in an ST120 ...

I just dropped a note to Upscale:

Just so you're aware of issues using the Phillips 5R4GYS in the Latino ST120 and ST150 amps, I know of three early failures (including mine), using the Phillips tube. They'll bias up fine out of the box, but get progressively weaker, and fast, to the point where they won't provide adequate power.

You may wish to correct your website to reflect that it is NOT a good substitute for a GZ33 or GZ37 rectifier, at least for the larger Latino amps, any of which work fine with the GZ33 or GZ37 tubes.

Somebody else mentioned the published reviews on the site ... looks like 5 stars all the way!  

Thanks for lookin' out for the peep's, Skiz! You definitely did your part.

Given the large number of posts on rectifier failures, and potential musical impact, why would anyone run a tube rectifier. A SS rectifier is cheap, durable, and matches the amps used in the sixties. The mid 60's Marshalls, HiWatts, etc, were mostly SS rectification. I run SS rectification in my ST-70, and it is the most reliable part of the amp! If you miss the glow of the tube rectifier, just hook up the filament, and throw a couple of diodes inside the amp!

Mike

sKiZo wrote:

wgallupe wrote:I don't think its fair to blame Kevin Deal or question his business practices. Its not his fault that the ST120 puts too much demand on most GZ34 rectifiers.

Yah but ... Upscale does list them as "The best buy and best made 5AR4/5U4G/GZ33/GZ37".

Yes, I drank this 'cool aid' and bought into all of their hype about the tube. Now I realize they are over stating things a bit. That will be the basis of my argument for returning the unused one. Now that I think of it, I should also ask for warranty coverage on the one that's going bad.

Skiz, good for you. Be interesting to see if Kevin reproduces it.
I remember, on another thread, Bob L. saying the 5R4GYS could maybe sorta work, but can't keep up with the Dynaco voltage swings demanded. And the out-of-the-box failure rate and gradual bias problems aren't the best.
Wonder if they'd be OK for an ST-70, though. If somebody wants to guinea-pig I have four still in the unopened shipping box they can have for $25 plus postage. PM if interested.
This is no slam on Kevin but I've learned to do my own tube research rather than just buying into his hype. I have a 6-year-old Ah! Tjoeb CD player from him that has performed daily and flawlessly. As for plain tubes, though, IMHO there are better sources.

There are 31 reviews of the Phillips 5R4GYS on the Kevin Deal/Upscale Audio website. 27 reviews give this rectifier tube a five-star rating. Yet there are at least three dissatisfied owners alone on this Dynaco website.  Unfortunately, the failures seem to occur after the 30 day warranty period.

I hope Kevin Deal takes notice of sKiZo's comments!! I won't hold my breath, however!!


Note: I turn 70 years old today! The older I get, the grumpier I get!

You get my vote for Surly Curmudgeon of the day!



You want it on a t-shirt, you'll have to print it yourself!  (mutter mumble grouse)

PS ... happy birthday! And several more to come!

Thanks for all the Birthday wishes!!

After a good night's sleep (9 hrs) and a terrific BM, I'm back to my usual cheerful self!!

As far as the Phillips 5R4GYS rectifier tube, it's probably just not a good choice for VTA amps.

Thanks,

Gregg R.

UPDATE on the 5R4GYS failures ...

I did get a note back that this was the first they'd heard of a problem with the Latino amps ...

PS ... Is it my imagination, or has any and all reference to the GZ33/GZ37 disappeared from this page?

http://www.upscaleaudio.com/philips-5r4gys-made-in-holland/

I'd still like to see an "exception" list as a substitute for the 5AR4 for certain equipment we all know and love. But ... baby steps ... baby steps ...

I also updated THIS THREAD with a warning to all ...

... and a happy holiday BM to all!!

sKiZo wrote:UPDATE on the 5R4GYS failures ...

I did get a note back that this was the first they'd heard of a problem with the Latino amps ...

PS ... Is it my imagination, or has any and all reference to the GZ33/GZ37 disappeared from this page?

http://www.upscaleaudio.com/philips-5r4gys-made-in-holland/

I'd still like to see an "exception" list as a substitute for the 5AR4 for certain equipment we all know and love. But ... baby steps ... baby steps ...

I also updated THIS THREAD with a warning to all ...

... and a happy holiday BM to all!!

Um, not exactly, Skiz. He lists $100 Mullard GZ-33s (a good price) but they're out of stock. But read down a little bit: "Attention! Before buying any 5AR4, 5U4, GZ33, or GZ37, here is a hot ticket from Uncle Kevy: Buy the Philips 5R4GYS made in Holland."
And happy BMs to everyone, as well.