You were looking for an organic connection with your guitar amp, you need to start with a great clean tone. The SAPPHIRE is a single channel amp design, with bold and full-bodied clean tones.
This amp sounds really open, revealing and offer a unique tonal breath. You will feel the sound on your fingertips!
Tone stack allow you to adjust the three treble middle bass pots for a great deal of flexibility when dialling in.
Most of the tone stack tend to have a cut in the mids so we created a setting called « rough » this pot allows you to minimize the effect of the tone stack.
What makes this amp special is that the rough pot will cause the tone stack to have less and less effect as the rough pot will make the mids level up till you have a completely flat tone stack which will also help the amp to crank.
The rough pot is a “push pull” switch that allows you to pull to totally defeat the tone stack and the amp will be more aggressive, distorted and louder.
One of the amp’s qualities is also the tube driven reverb circuit.
The effect is full, deep and we tune the desired level of the reverb effect by ear while testing the amp before delivery.
The amp is equipped with a bunch of switches that allows you to experiment with different configuration such as :
Cathode - fixed bias
High or Low B+
Penthode or Triode mode
Different Negative feedback values
New Rotary Switch 4 presets
6L6 powered 40W (6550,kt88,6v6)
Pre- amp, reverb driver and phase inverter 12AX7 and 12AT7 can be adapted to taste
Single “clean” channel
Settings are:
Volume setting Treble middle bass Rough tone and reverb
Tube powered spring reverb
Push pull volume bright switch
low high B+ Switch (power voltage)
Cathode Fixed Bias Switch
Penthode Triode Switch
Negative feedback Switch
New Rotary Switch (4 presets)
2/4/8 ohm speaker output
Selected input and output transformers
Selected Reverb Tank
Fixed Bias Setting fully accessible and made to be done by yourself
Custom Made Painted Aluminium Chassis (2 mm)
Hand made Tolexed laminated wood cabinet
PRICE 3200 chf (excl.Vat)
Size cm: W51 x H30 x D24
Weight: 14 kg
Descrption
Specification
High- and low-tension switch, offers you to choose between two main B+ supply tension as High will be the normal tension and low will give about 50 volts less on the anode of the power tube and center tap of the output transformer as also less tension to the pre amp tubes.
With this switch you can travel through sound that is less aggressive, smoother, sweeter or growling cleans straight in to your face, tight and lots of dynamics…
and even brighter and sparkling if you use the “push pull” switch hidden on the volume pot.
We also implement a negative feedback switch that allows you to have 3 different feedback as Low, High and Normal.
We decided to use this mod since the Fender always had different values of the resistors on the feedback line due to the different speakers impedance value, so you would see the same circuit with different value because speakers would be 2, 4 or 8 ohms.
We thought let’s try this and see if we feel that the difference is interesting enough to make us implement a switch… and it was!
So we did it, it is really interesting to mess around with the switch …
You also find a penthode triode switch
Your output tubes are typically pentodes, meaning that they have five elements inside (plate, cathode, control grid, screen grid, suppressor grid). Pentodes (and beam power tetrodes, such as the 6L6/6V6 family) are very efficient.... The screen grid eliminates the capacitance between the plate and the control grid, which makes the tube more linear and controls electron flow more accurately, for more power.
Connecting the screen grid directly to the plate supply (same voltage as the plate) makes the tube function more like a triode, hence the name. It almost halves the maximum power, so people sometimes call it a half-power switch. The tube wastes power in triode mode.
At anything less than full volume, the difference between full and half power is not that noticeable. It definitely does not halve the loudness of the amp.
Triode mode on a pentode sounds thicker, mushier, less articulate and less loud, Some people think it sounds more bluesy
HIGH/LOW SWITCH
PENTHODE/TRIODE SWITCH
Negative Feedback
The amp also have a cathode and fixed bias
fixed bias tends to be louder and it has a crisper and cleaner tone than the cathode biased witch we think has a softer and perhaps more compressed sound
Cathode Biased amp do not require biasing to change power tubes.
Fixed biased amps require biasing to change power tubes as well as periodic bias checks to ensure they are working properly. and also you need to know that different bias setting as cold medium or hot will make you experiment into different reaction into the tone.
We provide explanation and charts and bias calculator method to help you make your own opinion on that, and never again been dependent to a tech to make you own the precious tone amp …
Cathode biased amps are less efficient than fixed bias amps.
CATHODE/FIXED BIAS SWITCH
Rotary Switch 4 positions
This new feature allows you to have 4 different presets. By this switch you will have the possibility to have of course the Sapphire position and 3 other presets which are :
- SRV (Diaz Mod)
- Blackface (Same as Vintage American standard Amps)
- An in between Blackface and Sapphire
So remember that this amp has been created with the tweaking guitarists in mind. The once that want to experience the quest of the perfect tone for him/her ….We all know how
subjective tone can be, let alone the fact that we're all playing vastly different gear and styles.
