crate v50 - anything to be concerned about?

[gatorbrit]

Hi, I am a new poster on the board.

I recently acquired a used crate v50 amp. Apparently all the tubes were replaced by a professional tech and it seems to work great. Very nice clean sound, but the overdrive channel is a little unruly.

Anyhow, I read that there have been issues with the switching power supply in these amps and I wanted to get anyones opinion on this.

For example, how hard would it be to put in a conventional power supply?

Thanks

Rich

[Eric]

I have the same amp, but it's on loan right now to another guitar player.

Duff can probably speak to your question about the power supply. I think he had some people look at it and say swapping it out was an impossibility due to the poor design. His PS blew and I think he got a V32 on warranty, but yeah...makes me a little gunshy.

I do think they sound pretty decent, however.

[Duffy]

Yeah. I loved my V fifty. But the overdrive channel was one of the reasons. It had the smoothest overdrive and tone. It was a great sounding amp for about two months then: FLASH, POP, the power tubes blew out catastrophically, supposedly. Taking out the switching power supply, of which no replacements were available, at ALL. Installing a conventional power supply wouldn't work, according to the pro tech, and he spent a lot of time trying to BUILD a switching power supply, to no avail.

I talked to the customer service tech at Crate headquarters and he agreed to send me a V32 Palomino 212 with Celestion Seventy/80 speakers in it, the cream tolex and gold trim amp. It was a eight hundred dollar amp, MSRP. No cost to me, or he would cut me a check for the 164 I paid for it: no hesitation on grabbing the amp.

He said that Crate was expecting to have some replacement switching power supplies made. If this happened I would want to know and I'd call Crate headquarters and ask about the replacement part.

Supposedly there was a bad run of Ruby tubes, which were stock; but I heard that there were capacitor problems as well. The Crate dude said that the amp design was an engineering compromise and a bad design to begin with. Therefore we got what we thought were great deals when they closed the series out for a couple hundred dollars a piece, not long ago.

I would have a tech look at the capacitors, and the overdrive should be old school smooth and thick and full sounding with no jagged edges.

Maybe the previous owner changed the preamp tubes.

Check the power tubes and see if they are Ruby tubes. If they are I would be careful. Also, I would turn it off immediately if you hear any popping noises or see any minor flashes or suspect anything is wrong.

If I had ANY question about the power tubes in any of my tube amps, from now on, I'm taking it in to a tech and getting new tubes if they are needed or even suggested.

Catastrophic power tube failure can cause a LOT of EXPENSIVE damage to any amp. Maybe some amps are more protected from catastrophic power tube failure than others, I would suppose so. Bad tubes probably blow out suddenly all the time. You just don't want them to take out other parts of the circuit and the power supply, etc.

They use switching power supplies a lot in solid state amps but they have not proven to be useful in tube amps, to the best of my knowledge. That's why tube amps are so heavy, one of the reasons; heavy conventional power supplies.

Good luck with it. The overdrive should sound beautiful, even outstanding. You might want to try swapping or using some different preamp tubes. Mine were all 12ax7's I believe. Maybe some heavy metal guy put in some different preamp tubes to get a ragged overdrive.

I really liked that amp a lot. But this Palomino is truly awesome.

[jim p]

I have one I have given to my son with the stock tubes not sure how often he uses it but it has had no problems. I did lower the fuse value in the B+ supply to a 300ma to 500ma fuse but needed to increase the resistor connected to the screen supply so it would not pop the fuse on power up. I would have to search around for the schematic I marked up to see what resistor I changed. I think the stock fuse is a couple of amps so the power supply has to handle quite a high load before the fuse would blow with the stock value. It is the same basic supply as the V33 head uses they just stuff different components into the board for different B+ voltages relative to the amp it is in.

[gatorbrit]

Thanks for all the great feedback. The previous owner bought the amp cheap in a non-functioning state and had the tubes replaced. I am guessing that it is OK now. But I won't be leaving it on when I am not in the room!

Thanks for all the feedback.

Rich

[gatorbrit]

OK - I checked the tubes.

The power tubes are GT 6L6 CHP
The other tubes are 7025 12AX7 WB

I know the power tubes are not stock, they are Groove Tubes, but what of the other 3? They say "Made in Russia" on them.

Thanks

[jim p]

The 12AX7 is the standard tube in the preamp and phase splitter in the amp. The 7025 is a low noise tube with most specifications similar to the 12AX7, so it is an upgrade.