doctorcilantro Posted January 18, 2005 Share Posted January 18, 2005 Hey folks, Considering a future upgrade from a Sherwood S-5000 integrated. Any recommendations on tube power amps that have XLR inputs. Price range is under 1,000$ but I'd like to stay under 750$ if possible. A min. of 40 watts should suffice for me. thanks, JC Link to comment Share on other sites More sharing options...
doctorcilantro Posted January 21, 2005 Author Share Posted January 21, 2005 bump .... Link to comment Share on other sites More sharing options...
Griffinator Posted January 21, 2005 Share Posted January 21, 2005 That's a tall order. Not many of the inexpensive tube amp options come with balanced XLR inputs, especially the ones that kick out 40 wpc or more... I, however, will defer to the experts on the bargain market... Link to comment Share on other sites More sharing options...
LarryC Posted January 21, 2005 Share Posted January 21, 2005 Why do you want XLR connections? Link to comment Share on other sites More sharing options...
3dzapper Posted January 21, 2005 Share Posted January 21, 2005 George Wright puts balanced inputs on his power amps, at least the Mono 10s. have. They can be found used in the $1000 range. The problem is getting a quality pre with balanced outputs without a second mortgage IMHO. YMMV etc. Rick Link to comment Share on other sites More sharing options...
sfogg Posted January 21, 2005 Share Posted January 21, 2005 Mark, "but there's little value in doing that unless every piece of gear you connect is balanced XLR. " I disagree, any time you have a balanced connection you get the CMNR benefits and grounding benefits between those two pieces of equipment. Maybe you have a ground loop problem between your amp and pre-amp... and XLR between those two would fix it even if your sources to the pre-amp weren't XLRs "I've seen consumer gear with XLR connections simply wired as "2-wire unbalanced" cables, and that is really stupid, IMO." Why? As long as the impedance is matched (balanced) on both hot leads at the source there is actually no need to put signal on both sides to get the CMNR benefits of a balanced interconnect as long as the receiving end is a typical balanced receiver. Think about it.... the whole point of a balanced connection is to reduce common mode noise and to help eliminate ground loops. If noise gets into the interconnect it will be on both hot leads regardless of if signal is on both leads or not. The receiving end of the connection will still invert one of the leads and sum it with the other lead. Since the noise is on both sides of the connection the inversion will put the noise out of phase with itself and when summed it will still cancel the noise out and you still get the CMNR benefit. The signal itself is uneffected since you are inverting one lead (with no signal) then summing that with the signal... end result is you get the signal. Now if the XLR wasn't impedance matched (IOW not a balanced connection) or really was just two wire then it would act pretty much like an RCA connection since noise wouldn't get into both lines evenly and it wouldn't offer much of any benefit above and beyond RCA except for being hot pluggable. Shawn Link to comment Share on other sites More sharing options...
D-MAN Posted January 21, 2005 Share Posted January 21, 2005 I don't know of any that I could possibly afford, anyway. Maybe an ARC or something in that price range. With my tube mono-heads having RCA only, and being that they typically end up quite a ways from the pre-amp, I always thought it would be a good idea. We've all seen the tube mono-heads sitting in front of the speakers in the magazine ads and such. But running an RCA to them would be quite a loss, I would think. DM Link to comment Share on other sites More sharing options...
sfogg Posted January 21, 2005 Share Posted January 21, 2005 Rick, "George Wright puts balanced inputs on his power amps, at least the Mono 10s. have." Have you ever opened yours up? From reading the Wright sound website I don't think the XLRs on that amp will give you the CMNR benefits of a balanced connection. It sounds like the Wright keeps the signal lines seperate to avoid the phase splitter in the amp and relies on the inverted phase on a balanced connection. Shawn Link to comment Share on other sites More sharing options...
sfogg Posted January 21, 2005 Share Posted January 21, 2005 BTW, if anyone wanted to gain the CMNR benefits of an XLR interconnect with an RCA only amp you can use something like this: http://www.jensen-transformers.com/pc2xr.html right at your amp(s) and run XLR from your pre-amp to it and you would gain the CMNR benefits in the XLR cable between the pre-amp and the Jensen box. Jensen also sells the transformers seperately and they could be built into an amps input if desired. The white paper section of the Jensen site has pretty good info on XLR and noise issues and such. Shawn Link to comment Share on other sites More sharing options...
3dzapper Posted January 21, 2005 Share Posted January 21, 2005 Shawn, I don't have the schematic and only looked cursorily at the XLR inputs from the insides as I have no match for them. From memory, the two inputs are joined by a summing resistor if that is what you mean. Rick Link to comment Share on other sites More sharing options...
sfogg Posted January 21, 2005 Share Posted January 21, 2005 Rick, " From memory, the two inputs are joined by a summing resistor if that is what you mean." You can't just sum the two hot leads in an XLR or you will potentially cancel out the signal if the source is putting the signal with opposite phase on both hots. On the receiving end one lead has to have its phase inverted (thereby putting both signal lines in phase again) then the two leads are summed. Shawn Link to comment Share on other sites More sharing options...
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