Diamond 300B tube guitar amp


The Diamond is a resonating tube amplifier for acoustic and electric stringed instruments.
Its unique design allows natural musicians to experience their own gift of harmony in ways that re-define inspiration.

Innovative and unique circuit design

Adjustable Resonance

Ultimate purity in signal flow

Unique custom made Transformers
by Mercury Magnetics

Highest quality components

Handwired point to point wiring

Class A 25 Watt / 55 Watt Peak

300B mesh plate output tubes

6J7G or 6K7G mesh plate preamp tubes

83 mercury vapor rectifier tube

Adjustable resonance

No-loss frequency range selector

Sprague Vitamin Q paper/oil tone capacitors

Carbon composition resistors

Sprague ATOM TVA filters

Point to point terminal cloth wiring

NOS tube sockets

Aluminum chassis 12 ga.

100,120,220,240VAC 50/60Hz
Handmade in USA

The Diamond emanates pure musical sound in crystalline transparency with an exceptional lively quality.
The signal flows freely without distortion, limitations and losses in power and frequency range
from the original source directly thorough the speaker to the listener's ears.
No capacitors or resistors are in the way, as with conventional tube amplifier designs.

Guitar players often dismiss high fidelity amplifiers, because they are simply not intended to interact with the dynamic range of guitar signals.
The Diamond's circuit, custom transformers and tubes are specifically designed and selected for stringed instruments,
allowing for a lively and musical response unlike a normal guitar amp that just uses 300B tubes.

The Diamond's unique design originates from the simple approach of the pioneer days of tube technology.
The direct interaction between tubes and transformers has a resonating effect on the signal.
Harmonics can be tightened or released to create an acoustic instrument-like natural resonance.

The input absorbs all the unique character of the introduced signal.
Unlike conventional tube amp designs, with typical compression and signal loss,
the Diamond embraces every nuance blossoming to full musical potential.

Claro Walnut cabinet with JBL D130 and Tone Tubby 8" Low Watt Alnico

Together with a Field coil speaker or a JBL D130 mahogany speaker cabinet,
the Diamond becomes the ultimate clean to overdrive tube amplifier for discerning musicians,
perfectly matching refined tone and accomplished technique.

"Chris, this combination of tubes, transformers and speaker is in the top 1% of the best tube gear ever made."

Sergio Hamernick - Mercury Magnetics

User Feedback:

Hi Chris,

Let me say that the Diamond into the JBL & Tubby 8 is fabulous.
I can hear each guitar's DNA & exactly the pedals that may be used.
The music just flows dynamically following each note.
I'm always happily surprised when I think the sound can't really get any better & it does, something you can only hear.
So, if you ever stop looking for something better, the Diamond is the best amp I've ever heard.
But as I like to say, Keep Working On It!

Congratulation, Excellent Job & Thank You!

Mel Bernhard

PS: I hope the rules change on how many pieces I can take to heaven so that I can bring The Diamond & Cabinet.
If not I'll still take the Midnight Special. I think I'll start lobbying to take them both. It would be great if you could take anything with a Siegmund Logo on it.

Sound Samples:

I made these Sound Samples showing various settings of the Range and Resonance knobs and a litte harmony in D.
This is the Claro Walnut Speaker cabinet with a JBL D130 and Tone Tubby 8" Low Watt Alnico.
The guitar is the
Suspense with both pickups and Volume and Tone up.
I upgraded a large diaphragm condenser tube mic with a Micro Tube, Neumann U47 replacement capsule and Jensen transformer plugged into the Simplex Mic Pre
No FX, EQ or compression and everything flat into the computer's sound card.

D-Harmony Settings: Resonance 4, Volume 1/2, Range 4

Range starting at 0 and going 3 steps higher at 12, 27, 42 and 52 seconds

Resonance starting at the lowest setting and going one step higher at 9, 19, 30 and 39 seconds

Early style head

Mahogany cabinet and JBL D130 and removable casters

Diamond Stereo Set - matched tubes and speakers, both cabinets made from one piece of striped mahogany
with grain running from left to right cabinet continuously, same with front panel veneers of both cabinets and chassis