Rogue Audio M-120 vs M-150

Brad,

I spoke to Mark and he said they had to raise the prices because they were not making a profit; it seemed they underestimated the cost of the upgrade.

The new price does include a new set of KT88's. I won't be using them much, since I have GE tubes in the amps now, but they'll be something else to play.

KP

It's a good idea to pull the tubes out regardless.

I've received the amps twice (once on purchase, second time to have an errant resistor replaced on one amp), each time they had been knocked around enough to break the tubes' "stems" off inside the sockets.

This did not affect the functionality of the tubes, but does make installing them more difficult. I ended up marking the base of the tube to make correct pin alignment simpler.

I don't mind getting them with new tubes; I'll probably play the 88's for a few months and then put the GE's back in.

KP

Yiroryos,
Many (myself included) have found VSR speakers to match very well with Rogue gear.

I'm using VR4's with the upgraded drivers. I can only comment on their match with the 120 Magnums, which is wonderful. I am looking forward to their return as 150's.

As a plus, Albert von Schweikert, like the Marks at Rogue, will answer emails, return your calls and is a gentleman.

KP

Brad,
thank you for the excellent follow-up.

I'm expecting (hey, do I look radiant or what?) the amps back soon. They've been gone for three weeks.

It'd be interesting to see how the KT88's match against the JAN GE 6550A's.

I'd also like to try some el34's in there eventually.

I tried running the amps in triode, but I found them too mushy and lacking impact so I've been running them in ultralinear. I will try he new and improved 150's in triode and see how that works out. Can youth change the mode while the amps are on?

Funny thing with the 120's, I first got them they would run hot has h-e-double-hockey-sticks, then I switched from the EH to Svetlana tubes, and the heat dropped by at least 75%. It was so bad at first, I had to keep the AC on and the door open! Heck, standing with bare feet on the floor close to the amps would feel hot, and you would not want to put your hand anywhere too close to the tubes.

I have since tried the EH tubes, and they ran fine without too much heat. Not sure what changed to cause that difference. Maybe they had to "break in" first dot dot dot question mark.

KP

Brad,

I got them yesterday.
I wish I could make a true comparison of before and after, but I made a major change while the amps where gone by adding a wonderful Audio Note DAC.

Like yours, mine came with EH6550's, instead of the KT88's I expected. I have a set of those tubes already,and I can't say I cared for them. Rather dry sound. So I will be sending them back.

Well, I guess I can say it's better since the 6550's didn't sound as bad as I remember them from before. They do run slightly cooler than the 120's (keeping in mind my odd experienced with the 120's as I mentioned above). The biasing is not difficult, even with the do-hickeys placed in the back of the amp they can still be biased through the front.

I found that after all the tubes were biased it was wise to check them all and do another round of adjustments.

Did yours have a lose screw in the front-middle of the case? It seems the face plates don't have the threading for a screw there, but they just dropped the screw in anyway.

I am using GE 6550's now, and I love the sound. But like I said, I can't really do "before/after" with any degree of credibility.

One thing that I really like, is the ultralinear-triode switching on the fly. It was pain before, having to turn off the amps and take out the tubes. That's something else that's different.

Before, UL was clearly better for me, but now it's not so obvious. I'll have to play around with that for a few days before I can decide. Early impression is that the bass seems a touch fuller in UL, but in triode the mids and overall textures appear to be slightly more detailed.

KP