"Cymbal" 8W Amplifier (discontinued)
The Cymbal monoblock power amplifier is a unique and modern push-pull design using ultra-linear 6H30 triodes in a zero-feedback circuit. The uncommon circuit is optimized for sonics rather than raw power. Perfect for efficient drivers and horns, its eight watts of output power are extremely well-controlled by virtue of an astoundingly low 1.6 ohm output impedance (8 ohm tap). Overdrive into clipping is soft with a clean recovery. The input stage is fully differential and has a ground-lift switch to eliminate pesky ground loops.
The monoblocks are built in mirror image pairs. A second input offers capacitive coupling and can be designed to a set high-pass frequency to match systems requiring a subwoofer. Plenty of high quality iron is used in this design, including a fully choke-regulated B+ supply.
The Cymbal is not an "el-cheapo" amplifier, rather a fully tricked out and substantial product. The half-kit DIY version will cost you approximately $550 in raw parts each.
Is the Cymbal right for you? Yes, if you have efficient speakers with a reasonable impedance curve. If an SET works for you, then a Cymbal will be perfect. An example of an easy speaker to drive is the BK-16 from Madisound. Or the remarkable Horns at The Horn Shoppe.
|Power||8W into 8 ohms|
|Input Sensitivity||1.5Vrms (15dB gain)|
|Input Impedance||47k ohm|
|Bandwidth (-3dB)||10Hz to 95kHz|
|Distortion||0.18% @1kHz @1W|
|Size||7.25" x 11.65" (PCB)|
|Input Voltage||100V, 110V, 120V, 200V, 220V, 240V|
|Tubes||6H30 x 5, 5AR4 x 1|
"The Cymbal sounded quick and agile. It had good bass extension and control with the JBLs. The highs were extended and fairly smooth. Midrange coloration was minimal. I would place this amplifier in the resolution-over-romanticism category, although it sounded quite smooth and pleasing - somewhat reminiscent of a good SE amplifier in the same power range. It is a neutral, truthful, balanced sounding amplifier that will allow the user to listen relatively deeply into the music with appropriate loudspeakers. The Cymbal's low overall distortion and lack of compression (until it ran out of steam) belied its power rating, and will play convincingly loud with any speaker of reasonable efficiency." - Kevin Kennedy
Read the entire article at Positive Feedback Online.
The Cymbal amplifier has low distortion despite using no feedback. This is due to the superior linearity of true triodes and remarkable circuit design. Distortion is mainly 3rd order, just 0.18% at 1W.
The 10kHz squarewave response is near perfect. Very wide bandwidth for a tube amp.