This review page is supported in part by the sponsors whose ad banners are displayed below |
 |
 |
Description: The Tenor Audio 175S is a Canadian stereo amplifier hand-assembled in Quebec. Its power is quoted modestly as 175W into 8Ω, 350W into 4Ω and 650W into 2Ω whilst being a very big and heavy amplifier (weight is 54 kilograms). The fascia is Cherry wood finished in high-gloss varnish and extends to the top-cover strips. On the front a large round cut-out with the Tenor logo lights up red upon power-up and changes to blue when the circuit has stabilized after three minutes. The company specifies 60 minutes for full thermal optimization. The sides hold massive heat sinks covering the full 70cm length of the unit. The top cover gets a lot warmer because plenty of tubes working at high voltages create significant heat.
|
 |
The back panel is crowded with single Platinum-plated WBT 0702 Signature terminals and WBT 0201 Topline RCA and Neutrik XLR inputs. Below those a set of switches determine multiple grounding schemes to optimize operation in various systems. Talking about the power mains, it‘s worth noting that the IEC is of the 20A and not usual 16A variety. This requires a matching power cord. Above it is a mechanical power switch. We also get an operational hour counter to assess remaining tube life. The valves are said to be good for 10.000 hours without sonic degradation before they need replacing. There is a standby switch below the front panel as well as a mute switch. It seems that the whole enclosure is made from thick aluminum sheets.
|
 |
|
|
|
|
 |
Inside we see separate PCBs for each section. From the inputs the signal runs to the input board’s balancing transformer because the amp’s circuit is dual differential. There is also a protection circuit to safeguard against all known failures. From there using wonderful professional connectors we arrive at the tube PCB which isn’t hard bolted but mounted to elastomeric elements.
|
 |
The input runs two NOS Mullard 12AX7/ECC83 double triodes into four JJ ECC99s equipped with tube dampers and heat sinks. This is a proprietary tube from the Slovac factory specifically designed as a 300B driver and similar to the 6H30 so-called super tube. With four double triodes per channel, Tenor achieves high voltage gain, low output impedance and high input impedance, i.e. the OTL idea.
|
 |
Medium-power triodes like the ECC99 are not power triodes but in a circuit with transistor current gain, perfectly sufficient. Tenor claims that they output a full 10 watts in class A – more than the entire 300B Reimyo and only 6 watts less than the paralleled Ancient Audio. The board is peopled with top quality resistors from Dale and polypropylene capacitors from Wima and Vishay. The main power supply is exceptionally butch and bolted vertically with its back to the output stage to shield it from the 1.875KVA transformer which is contained within a potted copper can.
|
 |
That’s why the IEC socket is a 20A specimen. This oversized transformer carries many secondaries to supply discrete voltages to each section. Channel-specific filtering banks are mounted vertically to the heat sinks as are four complementary pairs of Toshiba 2SK1530 + 2SJ201 Mosfets per channel. Ribbon cables couple those directly to the loudspeaker terminals.
|
|
|
Upon first looking at the amp's internals, one's
attention is instantly drawn to the massive power supply with voltage stabilization in all possible junctions. This amplifier is huge but very well made. Naturally, we cannot get around its substantial cost but that’s a mostly academic point for most. Here one isn't buying a bucket of nails but an absolute reference product. That comes at a price. The amp ships in a terrific professional case like stage equipment.
|
 |
|
 |
Technical data from the manufacturer:
Gain: 32dB RCA/30dB XLR
Power: 2, 4, 8Ω (1 kHz): 650, 350, 175W
Signal to noise ratio (10W*): -94dBA
Signal to noise ratio (full power*): -115dBA
Frequency response: 3-200 000Hz (± 3dB)
THD + N (5W/20-20kHz): < 0.10%
THD + N (10W): < 0.08%*
THD + N (175W): < 0.25%*
IMD SMPTE (10W): < 0.5%
Channel cross talk (1kHz): < -100dB
Input impedance (1kHz; XLR/RCA): 20kΩ/33kΩ
Output impedance*: 0.16Ω
|
|
Damping factor*: 50
Working in class A: 13W *
Input sensitivity (175W, 8Ω, 1kHz): 1.3V XLR/1.5V RCA
Maximum power consumption: 1850W
Dimensions: 710 x 500 x 210mm
Weight: 53.5kg |
opinia @ highfidelity.pl
|
|
|
 |
 |
|
 |