6v6 single ended amp in triode?

[OO1]

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[OO1]

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[Alex Kitic]

26 minutes ago, Randyh said:

great advice

A better advice would be NOT to have 3 grounding points to the chassis!

You should have only one grounding point.

If you measure the voltage between these points (AC, mV range) you will understand why. That is the source of hum, and the more sensitive/efficient your system is, the more painfully you are going to be aware of it.

All ground should flow to one point, either as a star or as a bus - and if you are earthing your chassis (connecting to mains earth) this should happen in the same point as all the grounding.

[OO1]

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[Alex Kitic]

6 minutes ago, Randyh said:

works for me

And it works for many manufacturers - but it is sub-optimal.

If everyone did a perfect job, this would be a perfect world.

It depends on the application - hun would be painfully audible with efficient speakers, or if not masked by other issues (stronger ground loops, inefficient PS filtering, hum from direct heated tubes... and a lot of other hum/noise/buzz sources too often neglected not only in DIY but products as well).

 

[codewritinfool]

I'm not a tube expert.  Not even a tube novice.  I can, however, read schematics.  Started as a component-level bench tech in the late 80's working on satellite communications gear.  I moved to the engineering side and have been there ever since.

 

 

These topologies look essentially the same to me.  Furthermore, the circuit modification as described and as implemented seems the same to me too.

 

 

[Marvel]

At the same time, this would be a bit hard to prove. I've looked a multiple dozens of schematics over the passed 30 years and there a lots of similar, or "almost " exact copies of schematics by different people.

[moray james]

3 hours ago, Marvel said:

At the same time, this would be a bit hard to prove. I've looked a multiple dozens of schematics over the passed 30 years and there a lots of similar, or "almost " exact copies of schematics by different people.

a SET 6v6 is a wonderful sound but I have a soft spot for a 6v6 run as a pentode rather than as a triode. a very nice audio tube indeed either way.

[mike stehr]

 

 

[Alex Kitic]

On 4/11/2020 at 12:15 AM, mike stehr said:

 

 

 

Thank you for posting this. I was aware of the thread but did not want to post it myself.

Are you still using the RH84 you have built?

And, have you considered modifying your console amp (the one painted white) into an RH84? Many people have modded these Magnavox consoles to RH84 with considerable success.

[Alex Kitic]

By the way, guys - have you noticed all my posts mentioning how my RH84 schematics was shown by Matt Formanek as his own (for an 6V6 amp that would not work that way anyhow, at least not for long due to the g2 voltage being too high...) have disappeared?

 

That was my reaction to this post:

On 11/16/2015 at 1:44 PM, ToolShedAmps said:

 

That's strange, isn't it?

How does it make look - from your view?

 

[codewritinfool]

I have noticed.

[mike stehr]

12 hours ago, Alex Kitic said:

Are you still using the RH84 you have built?

And, have you considered modifying your console amp (the one painted white) into an RH84? Many people have modded these Magnavox consoles to RH84 with considerable success.

 

Yes, I still have the amplifier. Sounds good.

 

The white and black Magnavox console amplifiers were sold...needed the money.

I still have the output transformers from a parted out integrated Heathkit single-ended 6BQ5/EL84 amplifier. I had planned on building another SEP 6BQ5 eventually.

 

Trying to finish the half finished projects first...