Rowland model 5 vs Threshold S500 series II




Hello All,

Looking at both amplifiers , any input as to which is preferred and why . Speakers are 2 ohm ribbons ..

Regards,

Wayne
weseixas
Hello,
Thanks for the response, most on the apogee forums recommend the Krell ( early) and the Rowland 5 /7 . I like the sound of the Threshold myself and have never heard the Rowlands .

regards,
I looked at the JRDG Model 5 manual and found the following relevant information:

Damping Factor
Greater than 175, 20 Hz to 20 kHz, 8 ohms
Greater than 60, 100 kHz, 8 ohms
Output Current
40 amps peak, continuous
90 amps peak, 0.1 ohm, 20 msec, 1 kHz
Overall Gain Selectable: 20, 26, 29.5, 32 dB
Sensitivity 36 mV, 1 watt, 8 ohms
Input Impedance Selectable: 100k, 20k, 600 ohms
Common Mode Rejection
Ratio
Greater than 90 dB
Bridged Mono Output
Power
550 watts RMS continuous, 8 ohms
800 watts RMS continuous, 4 ohms
1000 watts RMS continuous, 2 ohms

Interpreting the specs, from a power handling, the JRDG Model 5 should not have major problems handling 2Ohms ribbons, particularly when bridged to mono operations. On the other hand, its damping factor just exceeding 175 may indicate a certain propensity for warmth and perhaps unspecificity in the bass region. G.
as 5Weseixas, in answer to your query on Rowland Model 7, I have owned Model 7 balanced monos from 1998 to 2008. I used them to drive a pair of Magnepan 3As and then briefly Vienna Mahlers V1.5. Model 7Ms have amazing power and authority, but they can be faulted of being somewhat slow in the bass region for low impedance speakers like Maggies and Viennas. I have found the following information in the Model 7 manual:

Damping Factor Greater than 300, 20 Hz to 20 kHz, 8 ohms
Greater than 90, 100 kHz, 8 ohms
Output Current 50 amps peak, continuous
150 amps peak, 0.1 ohm, 20 msec, 1 kHz

A. Damping factor is almost twice that of Model 5, and continuous max current is 25% higher.
.

B. On the other hand, Model 7, unlike later Rowlands are balanced in the input phase, but not in the output at the speaker terminals. . . this means that the speakers membranes essentially are in free-fall during return excursion, as the negative amp output lead is not actively controlled.

So, in the end the Mod 7 is likely to yield somewhat greater authority than Model 5, but the greater damping factor being offset by a half balanced design is likely to yield very similar level of speaker control.

f