Rowland model 5 vs Threshold S500 series II

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.
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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

Hello Guidocorona,

Thanks for your informative response.

No problem Weseixas, PM me if you req further info. G. 

Have had the Threshold S/300 Optical bias, the SA/1 mono's currently and model Rowland model 7's.
Threshold has never been very strong at 2 Ohm loads.
The model 5 can deliver more current then the S/500 it sounds more polite then the S/500.
According to J. Gordon Holt the Threshold S/500 was superb on Acoustat. So if you want a more laidback and smoother presentation I would go for the Rowland. If you want a more vivid and detailed one I would go for the Threshold.
They probably, the Rowland certain, will drive a 2 Ohm load (if it behaves like a Magnepan) both of them.
Success

If you have the opportunity to buy the 500/II or even better I think it was called the 550 ? BUY IT! You'll need to put a good pre on it, but it is much better than the Rowland 5. Havent heard the 7, but the 500 was a great amp! It sound staged, had fast bass and extended on both ends to infinity. Must be partnered with a non edgy pre. A good tubed unit or actually a Rowlnd Capri would be killer in that! In addition, I think service will be easier on the Threshold as Jeff doesn't want to work on the old stuff and there are several companies who perform outstanding maintenance and mods on the Threshold stuff.