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My friend has an amp that uses the 5U4G rectifier tube and apparently they aren't lasting very long. Can someone here help me by suggesting a direct drop-in replacement that might last longer and sound as good or better? TIA for all who help...
I'm listening to: Written In The Rocks by Renee Rosnes
Thetubeguy1954 (Tom Scata)
Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers
Follow Ups:
If you have a schematic or a good picture of the amp that would be most helpful.
You might give us the type of amp or brand name.
Is it a usual problem or did the problem just come up.
Whether the amp has a problem or not, it would be hard to just recommend something as most 5u4, when used within their designed capabilities will last a very long time. I mean i have not run across an amp where a USA made 5u4 had failed other than from shipping and handling damage.
Edits: 12/17/16
Hi DAK!
Sorry but I still don't know the specific model of amp it is. But I do know it's a Cary amp!
I'm listening to: This Girl's In Love by Rumer
Thetubeguy1954 (Tom Scata)
Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers
I believe I have read here that Cary was notorious for using too much capacitance in the first filter cap which would be hard on the rectifier.
Just a WAG.
.
Freak out...Far out...In out....
Notorious is being very kind. Nucking futz is (IMO) more accurate.
The schematic and a picture of the unit are needed. Major field engineering changes (FECs) may be required.
Eli D.
If the power supply is cap loaded for a 5u4 the value of the first cap is only 40uf for 5u4gb, @ 225ma x 470vdc. So, any of those numbers exceeded will lessen the lifespan of the tube.
DAK,
I'm sorry I still don't have an answer as I haven't heard back from my friend. All I do know is it's a Cary amp!
I'm listening to: This Girl's In Love by Rumer
Thetubeguy1954 (Tom Scata)
Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers
More than 1 Cary product TOTALLY disregards data sheet limits, with unpleasant consequences.
Getting the 1st cap. value inside published limits is an important 1st step. Another consideration is that current production, Russian and Chinese, ST bottle "5U4s" frequently arc over, when used with a capacitance that is not excessive. :> (( The only current production 5U4 that is satisfactory is New Sensor's 5U4GB (cylindrical bottle) sold under the ElectroHarmonix (EH) label. OS ST bottle 5U4s are quite costly. However, the excellent GE 5U4GB is available at a "rational" price.
Eli D.
Yes, but his friend is eating rectifiers. That's unusual.
5u4 is a very tough tube.
Thanks Bouncy,
I'll tell him that!
Sorry but I still don't know the specific model of amp it is. But I do know it's a Cary amp!
I'm listening to: This Girl's In Love by Rumer
Thetubeguy1954 (Tom Scata)
Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers
It does not have a soft start, but if his friend is really going through tubes this is unusual. I'd look in the power supply, a bad or a wrong sized first cap could be the problem.
Hi Frihed89!
I sent my friend an email with your suggest and that of others here! Thanks for your input.
I'm listening to: This Girl's In Love by Rumer
Thetubeguy1954 (Tom Scata)
Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers
Is the 5U4G or 5U4GB the suggested OEM rectifier for this amp?
Thanks!
Hi Fender!
I believe it must be. But I honestly don't know because as of this moment. All I really know about this problem is it's a Cary amp! However once he tells me what specific model of Cary amp it is, I'll let you guys know!
I'm listening to: This Girl's In Love by Rumer
Thetubeguy1954 (Tom Scata)
Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers
An amp designed to use a 5U4GB, will prolly burn out a 5U4 or 5U4G. Pretty big difference in current delivered.
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