Two Rock Emerald Pro

[Decko]

Hi All,

Played a tele through an Emmy Pro today. It was an awesome experience.

Finished up an Express build recently and would like to start the next build within the same vein as this Emmy.

Since I am new to this side of the forum could you kindly point me toward the schematic or the correct Dumble build?

Thanks,

Decko

[boldaslove6789]

The Emmy Pro is basically a 50w Skyliner HRM with a Fender style reverb circuit and half a Dumbleator ( 2 12ax7's for Reverb (using only 3 of the triode's), the remaining triode is used for the half a Dumbleator).

[brentm]

Here's some amp pr0n I picked up along the way with Emerald Pro in it. Everyone has had similar experiences/reviews of the Emmy Pro.

I'm not sure these pics will get you any closer... but you can kinda see what's going on in there.

[Structo]

Gawd, it is so strange that an amplifier that looks like a sixth grade science class built it can have so many glowing reviews.
I guess the saying, "beauty is only skin deep" applies here.

That's pretty rich to goop the tone stack on a clone.

[brentm]

Yeah, one of the pics is without goop.

I always wonder about lead dress/craftsmanship on amps... Many of the amps I've seen built on this forum look amazing inside. I know Two Rock has made comments on the amount of wire in an amp, and less wire being better for sound. Is there any relevance to better sound using shorter lead dress and having a more compact circuit? I'm guessing you could eliminate several feet of wire by ignoring some of the pretty bend radii and just going as direct as possible just as long as you avoid potential issues with such lead dress.

[cbass]

Gawd, it is so strange that an amplifier that looks like a sixth grade science class built it can have so many glowing reviews.
I guess the saying, "beauty is only skin deep" applies here.

That's pretty rich to goop the tone stack on a clone.

You wouldn't want someone to clone your clone now would you.

I would never buy anything thats gooped.How in the hell are you supposed to fix anything when a component goes bad?

[topbrent]

Here is a bit of info on the emmy.

https://tubeamparchive.com/viewtopic.ph ... light=emmy

Any more details on the half a d'lator thing? Return only?

[ToneMerc]

I always wonder about lead dress/craftsmanship on amps... Many of the amps I've seen built on this forum look amazing inside. I know Two Rock has made comments on the amount of wire in an amp, and less wire being better for sound. Is there any relevance to better sound using shorter lead dress and having a more compact circuit? I'm guessing you could eliminate several feet of wire by ignoring some of the pretty bend radii and just going as direct as possible just as long as you avoid potential issues with such lead dress.

When I see TR guts I don't see the shorter wires perse', to me there's a fair bit of excess wire and nor are the circuits that compact. Really what I see is let's make it as cheap as possible and mask the circuit layout. However, I think an amp can be laid out in different ways which each having it's own signature and still sound good.

TM

[martin manning]

Here is a bit of info on the emmy.

https://tubeamparchive.com/viewtopic.ph ... light=emmy

Any more details on the half a d'lator thing? Return only?

I'm interested too... Some old Fender designs had an extra stage after the reverb recover triode that basically mixed the wet and dry signals. Is that what you mean Greg?

Also the 2006 schematic linked doesn't show the reverb, so where does that fit in? The gut shots also show three trimmers over by the PI. I'm guessing one is the PI balance and the other two are individual bias controls?

[martin manning]

When I see TR guts I don't see the shorter wires perse', to me there's a fair bit of excess wire and nor are the circuits that compact. Really what I see is let's make it as cheap as possible and mask the circuit layout. However, I think an amp can be laid out in different ways which each having it's own signature and still sound good.

TM

Stating the obvious, and to your point, a really neat wiring job in a hand-wired amp like this is really labor "expensive". As long as the critical details are attended to, a sloppier appearance is acceptable. Those of us doing this as a hobby or at least not for any real proffit can afford to build for "show" as part of the fun.

[brentm]

Quick note: The Two Rock Emerald Pro manual states there's a switch to go from series to parallel on the loop.

ToneMerc: I'd have to agree. It is probably an effort to get amps out the door without spending too much time on them.

[renshen1957]

I always wonder about lead dress/craftsmanship on amps... Many of the amps I've seen built on this forum look amazing inside. I know Two Rock has made comments on the amount of wire in an amp, and less wire being better for sound. Is there any relevance to better sound using shorter lead dress and having a more compact circuit? I'm guessing you could eliminate several feet of wire by ignoring some of the pretty bend radii and just going as direct as possible just as long as you avoid potential issues with such lead dress.

When I see TR guts I don't see the shorter wires perse', to me there's a fair bit of excess wire and nor are the circuits that compact. Really what I see is let's make it as cheap as possible and mask the circuit layout. However, I think an amp can be laid out in different ways which each having it's own signature and still sound good.

TM

Hi,

I agree with your insights

Some afterthoughts:

The major Amp manufacturers originally went to PCB for consistency, (to eliminate unit to unit variation from lead dress) and to save money spent on labor from hand wiring up amps.

Every wire can act as an antennae to radiate and receive. Proper lead dress, shielded cable, and a properly grounded circuit reduces/eliminates the above design concern.

Compact circuits aren't necessarily an ideal; the closer you stuff the components, the more likely you will change the parasitic capacitance between these components. Too close and Oscillation becomes an issue. When Marshall switched from Turret Boards to PCB, the company kept the same spacing between parts (for assembly reasons rather than for good electronics) consequently the parasitic capacitance did not change and affect the sound.

Although one doesn't want a rat's nest, too short a wire makes repairs/modifications a drag. I know copper and silver (coating on Teflon wires) have gone up, but it's not like the wire is blood.

The accountant has more influence on Amp design than the electrical engineer.

Best Regards and Happy New Year

[ToneMerc]

The accountant has more influence on Amp design than the electrical engineer.

Best Regards and Happy New Year

They have a great business model that works, it just I when see some of the component/hardware selections it goes against the price tag that they carry. It just goes to show that the final price doesn't always proportionally reflect the sum of the parts. Also, I think that we here are more critical than the general "non-guts" consumer.

Likewise

TM

[Decko]

Hi All,

Thanks for chiming in.

Is the link that topbrent post an accurate schematic?

Sorry, I am new to the Dumble thing...

Dumbleator would be a reverb circuit?

That said, I drank the cool aid. I am preparing for this build!

Has anyone on this forum attempt this build?

[boldaslove6789]

Hi All,

Dumbleator would be a reverb circuit?

Has anyone on this forum attempt this build?

The Dumbleator is a Tube buffered Effects loop. it helps interface Line level effects by matching impedance levels in the amps FX loop.

Jborders (Jason) who's supplied board sets for the amp garage built a clone of an Emerald Pro a while back AFAIK. Try searching it.