[Bumpy]

I have Ron Welborne DRD 45 monoblocks.

I was looking at the driver tubes today to discover they are GE 0528s. Now the manual says they should be 6N1P, so I search to see if the two types are equivalents as one reviewer says that there are really no drop in equivalents for the 6N1Ps.

So, my searches reveal that the GE 0528s are the same as the GE 6414s and are equivalent to the 12AT7s, but there is no link to the 6N1P.

Can anyone help?

Thanks

[FullRangeMan]

12at7, 12ax7 etc are all 12V tubes.

6n1p 6n2p 6922 6dj8 etc are all equivalents tubes, all 6V tubes.

Maybe he are refer tô the 6n6p.

[Bumpy]

The numbers I quoted are correct, both for the GE 9528 and the 6N1P..

I take it the 6 and 12 refer to the heater voltages

So do I have a 12 volt tube in an amp designed to take a 6 volt tube. Would that even operate?

[FullRangeMan]

Apparently 6414 is a 12V tube as 12ax7 etc

[Bumpy]

So where do I go from here.???

It was a Diy amp, so perhaps the builder decided to put in 12 volts to the driver tube. I guess there is a way to check this.

[FullRangeMan]

Dont check in the amp internals to avoid disaster and electric shock.
What do you want ?

[Bumpy]

Thanks for the warning.

I think the 12volt valve needs replacing. I have a few 6N1P that I bought as spares. If I put one in as replacement, will it go bang and wreck my amp.?

[FullRangeMan]

Well 6N1P is a 6V tube it dont will work.
https://tubesrule.com/products/6414-or-0528-raytheon-black-plate-3-mica?_pos=1&_sid=2de43b760&_ss=r

I guess there is a way to check this.
Check the datasheet of the damaged tube on internet.

What is the damaged tube ?

[opnly bafld]

You can check the filament/heater wiring.
If it has been working with a 12.6v tube, it will need to be rewired for a 6.3v tube.

[Bumpy]

I guess one option is to stick with a 12v tube as replacement.

Is there a good reason why a previous owner would have switched the build to suit the GE 0528 rather than the 6N6P?

[Bumpy]

Well 6N1P is a 6V tube it dont will work.
https://tubesrule.com/products/6414-or-0528-raytheon-black-plate-3-mica?_pos=1&_sid=2de43b760&_ss=r

I guess there is a way to check this.
Check the datasheet of the damaged tube on internet.

What is the damaged tube ?

The worn tube is a General Electric 0528

[Bumpy]

You can check the filament/heater wiring.
If it has been working with a 12.6v tube, it will need to be rewired for a 6.3v tube.

I fancy checking the heater voltage (carefully). Is this as simple as:

1. Find the 9 pin configuration
2. Identify the pins that carry the heater voltage
3. Remove the valve and turn on the amp
4. Put a meter across the selected locations

I don't know much about electronics, but I am very competent at any DIY stuff.

Thanks

[opnly bafld]

You can look at it, pins 4, 5, and 9, assuming the PT has a 6.3v tap.

http://www.valvewizard.co.uk/heater.html

[SET Man]

So where do I go from here.???

It was a Diy amp, so perhaps the builder decided to put in 12 volts to the driver tube. I guess there is a way to check this.

Hey!

    OK, so are you not the original owner/builder of these amp. Sound like whoever built these set modified them to take 0528 tubes. Depending on how the heater are wired up 12AT7, 12AX7 and etc can be run at 6.3V in parallel. But do check with people with more experience on tube than me though.

    Anyway, if the 0528 tubes sound good to you now. You might want to stick to it and look for some, maybe stock up a few pairs.

    By they way, I'm also a Welborne Labs SET amps owner. I have a pair of the Apollo monoblock SET. I'm the original owner bought new as a kit and I built them back in 1999! They just turned 23 years old last month!

[FullRangeMan]

I guess one option is to stick with a 12v tube as replacement.

Is there a good reason why a previous owner would have switched the build to suit the GE 0528 rather than the 6N6P?

This 0528 tube was a long life version and yet cheap.
The 6414/0528 is getting very hard to find, but with a 10,000 hour heater rating you may never need a replacement. Discussion groups rate this type very highly for use in headphone amps. Stands about 1/2 inch taller than the standard 12AT7 INCLUDES: (25) GE vacuum tubes, Model 0528 Date codes may vary (most have date codes from the late 1950's) Most say IBM 3000528
You said it was 6N1P now 6N6P.
6N1P, 6N2P and 6N6P are all Russian tubes very cheap and military quality. 6N1P and 6N2P are used in many Decware amps and preamps.