Mixed driver tube for Mcintosh MC275

I disagree with the discussion regarding V1. I was using the stock Mcintosh tube in this location. I was told that you did not even have to use a tube here if you were using XLR. WRONG! My amp would not even play in one of the channels without a tube in this socket. Then I put a telefunken tube in the stock tubes place. WOW, it made a huge difference, not a little one, so don't let anyone tell you that a good tube in V1 is not important because it is very important. If you do not believe me, try it for yourself

I have the MK IV so maybe it is different

I think the RCA sounds better

The Mark IV also has gold plated balanced inputs. The balanced inputs sound far more electric sounding IMHO in comparison to the natural sound of RCA's in any component. The balanced inputs have more gain but I am not sure that makes them better, different for sure. Some manufacturers still do not even use balanced inputs in their components. It was a major disappointment the new amp does not have the RCA's and attenuators. The lead free design is a good thing. I also think the old barrier post allow for a better connection, just not as many options. I could have had either but went with the older model so I can run a phono amp directly into the amp. I like this option. From what I am told, the mark IV and earlier models had their tranformenrs wound by the same person/people that wound the original models. Does anyone know if that is true?

I still have to say that putting a better tube in V1 does make a difference when using balanced inputs. It is not small either. You have to try it. Better bass and well, everything. I don't care what the schematic says, my ears tell me different. Take the stock tube out and put a spare tele in there and come back and tell me you do not hear a difference.

I spoke to McIntosh today and their tech support told me that V1 is definitely in the signal path when using balanced cables on the Mark IV so I now I know I am not tone deaf. According to Mcintosh, it is the circuit that determines whether you are using balanced or unbalanced. If you do not believe me, call them, they are easy to reach. I would like to see the schematics for this amp because I can read them. Are they available? Where would one find them? I know you can get the schematics for the original 275. So there you have it!

I know that I am not the only one that feels that RCA inputs sound better. I have spoke to others and they feel the same way. In the case of the MC275 which we are discussing, balanced cables offer more gain, otherwise, a waste of money. The MC275 is not a fully balanced amp so why would I want balanced inputs. If my amp was fully balanced, then it would make a difference, otherwise, it is a waste of money that I could use to buy records. I would not call it masking the sound. I also think the masking many hear is due to other factors such as the power cords. It is amazing what good AC power cords can do.

That may be true as I do not have the gain specs in my manual. It does say that the input sensitivity is 1.2 volts unbalanced and 2.5 volts balanced. The only time I would use XLR is if I needed to use a longer interconnect from the preamp to the amp. It is not a fully balanced amp so what benefits are there to the balanced connection other than if you need a long run to your preamp? it makes absolutely no sense other than spend more money that I could put towards more records.

Okay, after viewing the schematic, it is clear that V1 is not in the signal path. Then what am I hearing? Voodoo? I am obviously crazy! Now I am convinced as to not buy anymore tweeks because my hearing is somewhat flawed.

I thought I noticed a more full sound with the other tubes I used. This is crazy. I am going to put my one pair of balanced cables back into the amp and see what I hear. I did ask the tech and he did say it was in the signal path and would have an effect on the sound. I felt I was pretty clear on how I asked the question. My mind is obviously playing games with me. This is a very informative thread. Maybe I will try different balanced cables and see what happens. There I go again, tweeking.

I have the Cardas on the CD player. I am listening ( auditioning) to JPS superconductor 3 cables connected to the turntable. I can see how some can be critical of them. I have NOS Telefunkens in the C220, all Telefunkens in the 12ax7 position in the amp, GE 12at7's and Tung Sol 6550 in the 275.

I am going to plug the XLR's back in try that V1 thing again. If it still sounds different,

I have 2 RCA tall plate 12ax7s that I am not using. Maybe I should try them in the phono section. I do not find the Cardas to be as bad as you are saying. They are decent cables. I may try the Anti Cable interconnect. I cant go wrong for $100.00. If I do noy like them, I will sell them here. Many here are tossing their expensive cables in favor of them. They have spent much more than I on their systems.

Maybe I will try the RCA's in the phono section. The tellies are quite good and very neutral.