Ry Cooder Green Man

[J Luth]

Is there something available that is similar to the Ry Cooder Green Man or information on how to build something similar?

[tedmich]

Yikes, if its anything like the boutique preamps that Danny “Sage” Mckinney sells on his WEB site http://www.requisiteaudio.com its about $4-10k worth of hushed secrets and mumbo jumbo! The man sells 8ft of XLR for $400 and an amorphous "upgrade to premium components" for +$2600 on a dual mic pre. His remakes of Standel amps are more conventional looking, though not cheap at $3500 for a combo.

From the way Ry speaks about his Green Man it sounds more like an attenuating filter than a boosting preamp but the praise Ry throws at the preamp means its going to be a closely guarded design and probably never made affordably. Good luck sussing it out!

[nosaj]

Yikes, if its anything like the boutique preamps that Danny “Sage” Mckinney sells on his WEB site http://www.requisiteaudio.com its about $4-10k worth of hushed secrets and mumbo jumbo! The man sells 8ft of XLR for $400 and an amorphous "upgrade to premium components" for +$2600 on a dual mic pre. His remakes of Standel amps are more conventional looking, though not cheap at $3500 for a combo.

From the way Ry speaks about his Green Man it sounds more like an attenuating filter than a boosting preamp but the praise Ry throws at the preamp means its going to be a closely guarded design and probably never made affordably. Good luck sussing it out!

I wouldn't be surprised if it was a tweed deluxe preamp driving the tweed deluxe or vibrolux.
http://rycooder.nl/pages/ry_cooder_I...ps_effects.htm
nosaj

[blind Blake]

its just a unit which has 2 tubes for the preamps, splits the signal with phase switches on each output and has a tone control and one volume to control both amps

[Chuck H]

its just a unit which has 2 tubes for the preamps, splits the signal with phase switches on each output and has a tone control and one volume to control both amps

This is not much help without a diagram or schematic. You mention tubes and phase splitting and demonstrate an auto transformer with undefined switches installed. Nothing definitive or explained here at all.

[Chuck H]

Further... Why would you need switches on a Variac type transformer? There is more or less voltage at the output as it is. What could the switches be doing differently considering the limited intention for this unit? Is this variac being used as an attenuator? I smell something bad.

[Mick Bailey]

It looks like it's been gutted and is used as an enclosure for the preamp and has none of its original function as a Variac left.

[blind Blake]

That's right, its been gutted and only the enclosure is being used. This arrangement of components most likely creates hum/noise. So to sum up - it's two valve preamps with a transformer to isolate them both then each output has a phase flip switch. It has an overall master volume to control the level of both outputs so you can plug in two amps and if say one guitar is louder than the other you can adjust the volume on the unit accordingly. You can also use it to lower the volume like an attenuator (even though it is not actually an attenuator). It adds a little push/boost as well.

[Chuck H]

Ah. Ok. I guess I didn't look close enough to see it's been gutted. Thank you.

[blind Blake]

I will research this further to see if I can make something similar and report back.

[Chuck H]

Well we have to break down what it does. From what I've read there are two tubes. Ok. It can go from zero signal up to a generous boost. The tone control can also boost the signal at extreme settings. There are two outputs with independent phase options and a master volume.

Making something that has all these attributes shouldn't be hard. Probably harder to stick it all in a Variac case The most interesting feature to me is the independent phase options for each output. And I can guess where that came from. Ry likes to use two different amps at a time sometimes. Not all amps have the same phase alignment. If the two amps you wanted to use are out of phase with each other that could be a problem.

It's bound to be a simple circuit because ideally you would want some way to differentiate the outputs for more control dependent on the amp you're feeding it to. Since not all amps have the same gain characteristics either. Since that wasn't done I have to assume the shortest route possible was taken design wise. Starting to think Jason has it with the simple tweed preamp. The phase options might be nothing more than inverting unity gain stages that can be switched out. Pretty sure there's no silicooties in there other than maybe a diode rectifier since that would rub Ry the wrong way (say THAT ten times fast ).

[Helmholtz]

To facilitate phase switching with unbalanced outputs each channel either needs a phase splitter (PI) or an output transformer.

[Chuck H]

To facilitate phase switching with unbalanced outputs each channel either needs a phase splitter (PI) or an output transformer.

It actually could be done as I described, BUT the output impedance would be inappropriately high to run cable to the slave amps without undesirable HF loss. So I'm thinking you're onto something with the output transformers. I vaguely remember reading something that hinted that way too but had no luck retracing my steps just now.

[Helmholtz]

It actually could be done as I described,.

What do you mean if not a Concertina/split load (or other) PI?
A unity gain CF does not provide phase inversion.

[Chuck H]

What do you mean if not a Concertina/split load (or other) PI?
A unity gain CF does not provide phase inversion.

With two dual triode preamp tubes there are enough gain stages to do a 5E3 instrument channel and then follow with dedicated triodes buffered for unity gain. Since phase is inverted through each triode bypassing either would effectively give phase options for two outputs. One way to avoid the consequence of HF loading due to separation resistors would be to make each triode a virtual earth type circuit so the separation resistors also act as series resistance for the VE circuit. This has the consequence of making one phase option a lower impedance than the other though. Of course if you bypassed both triodes you would have a mono signal run to both outputs, but what would it matter at that point. Independent phase inversion still achieved. But I really think your notion of the builder using transformers is more likely. So what are the extra gain stages doing at that point? Maybe cathode followers to allow more current to drive transformers?