Jeff Rowland Model 1 info

Wow, I didn't know there were two series. Is there any way to tell which version I have?

It's a long story how the amp came to me, but I basically didn't know much about it beforehand. Actually, I still don't, so any info you may have that isn't on the JRDG website would be appreciated. The reviews I read were all favorable, but none of them tested the amp out in bridged mode. One did make mention of a claim that unlike most amps, there is little or no sonic detriment involved when bridging this particular amp. Any truth to this?

Thanks in advance.

Just a quick addendum. I do remember an email exchange with Rich Maez (sorry if I mispelled his name) where he mentioned that the first series hummed audibly if you used the single ended inputs without shorting the balanced ones. Since I have not experienced this humming, is it safe to a assume that my amp is from the latter series?