Congestion, clarity problems gone: M.R. RM-9

Background: Just thought I'd post a followup. I was posting a couple months ago about my 8B, PV-5, ProAc One SC system being "congested," "not open enough," "thick." I got a lot of good suggestions here, including getting better wire (will still get some Mapleshades but never did yet), and trying a less colored preamp. I did try a SS amp, a B&K ST-140. It did not solve there problems, and was actually a lot like the 8B but without the smoothness and palpability of tubes. I still thought a different amp might be the answer, but kind of decided to stay away from an SS amp for now, and decided to go the route of trying a passive peramp, to see if the PV-5 was the limiting factor. I started researching the Slagle and Lightspeed stuff.

One amp that I had concluded might be a good candidate was a Music Reference RM-9, which had a reputation of being more neutral. They were way above my budget and I'd never seen one for sale anyway.

What happened: However, I did see one for sale, locally only in DC, Mk I, for a very good price. A week later he emailed me that he was willing to ship, and a couple weeks later, I am listening to it for the second day.

The congestion problem, in the same system, is just gone. I no longer feel that when the band all kicks in, especially with a lot of midrange stuff (vibes, guitar, keys), that everything gets congested, thick, or mushy and jumbled all together. Instruments aren't getting in each others' way. All instruments are always clear. They come from a black silent place, fixed in space, each filling the space, but each separate. I had some Vienna Acoustics speakers and with them it seemed like the instruments were separated into their own little spaces, like I could draw a few circles in front of me and the sax was in one, isolated, the vibes in another, etc. With this system they are all in the same space, but still separate, clear, clean, natural, accurate and pretty. I can hear details of any instrument I want to focus on, many that I could not hear before. I seem to be hearing all of the drums, not just the snare and a generalized tom. I hear the drummer hitting a sequence across all the drums. Cymbals that I thought were indistinct because they were quiet and in the background now are clear and separate and fully present from brass strike to shimmer, so I no longer need the cymbals to be out front as much. there is overall a timbral realness. The RM-9 is just a new level for me. Things are less lush than the Mac or 8B, certainly, but they are still warm and sweet and palpable, it just seems that they are not colored any more. Like a delicate desert without the honey, chocolate syrup, and whipped cream. Lush, fat, romantic tube sound is not essential to tube palpability. I like really warm jazz guitar, and the 8B, and even more the Mac, made all jazz guitar seem more warm. But now I hear what's there. On some CDs (Peter Leitch, From Another Perspective; Peter Bernstein on Ryan Kisor, Awakening) the archtops are as tonally warm, even hot, as could be, but on Peter Bernstein's Stranger in Paradise his archtop is more acoustic and wooden. It sounds accurate, like a real archtop guitar with its rich wooden resonance. Peter is in my opinion the best player currently out there. He does usually use a leaner, more acoustic sound. Heart's Content however is his electric warmest, and IMO best, CD. I have to get another one, as I gave mine to my teacher, so can't report on that.

For the first time Paul Chamber's bass sounds like distinct, clear vibrating bass notes all the down his walking lines on Kinda Blue: So What (Macero and Keyes). It's always kinda mushed into some indistinct soft bass energy before. What a thrill. This, on my ProAc monitors. Kinda Blue is the most beautiful I've ever heard it. The horns are clear but sweet and creamy. The brashness of the horns at the beginning seems smoothed out. Everything is like beautiful sweet colors on a black velvet background dimensional space. It seems to go back beyond my room.

I could go on and on. What an amp. What beautiful, sweet, crystaline clear music. I have no thoughts of further changes. Well, maybe some real wire :-).

Thanks for the update. The RM-9 is a great amp. Since you have the MkI version down the road you might consider sending it to Roger to be upgraded to MkII.
Hi Clio, I certainly have that on my agenda. I'm in no hurry though, as I'm just enjoying how great it is now.

It sounds like your 8B needs work, tubes or both.
The Marantz amp has earded its rightful historical appreciation and is a true collector item.
However if judging strictly on sonic merit the RM-9 is better sounding(as you discovered) due to better passive parts(Marantz has very good transformers). The RM-9 given your description very likely has a well designed and stout power supply. A 'good' tube power amp will provide the full realistic tone,timbre and natural color of instruments but avoid the overly warm lush and excess flab and sweetning. Seperation and clarity will be first rate without smearing and congestion. I find bass produced by the better built tube amplifiers to be most natural and honest without artificial 'slam' and dryness.The texture and nuance just sounds right.Testing different tubes could possibly improve the sound further.

I`m a huge jazz fan and can relate to your taste and happiness when it just sounds right.In my case simply upgrading my 300b tube (Shuguang Black Treasure to the Takatsuki-TA)my SET amp went from very very good to sublime music reproduction.
Your Marantz definitely needs work. I have worked on quite a few 8B's and when they are running properly they are simply amazing.
09-04-12: Clio09
Thanks for the update. The RM-9 is a great amp. Since you have the MkI version down the road you might consider sending it to Roger to be upgraded to MkII.
ach, I see Clio09 got here before me!! ;-)
With no disrespect to Clio09, IMO do *NOT* make the mistake of upgrading the Mk1 to Mk2. My friend had the Mk1 & after several years his curiosity got the better of him & he sent it in for an upgrade to Mk2 & that was a mistake, he admitted. The sweetness of the amp was gone in Mk2. The Mk2 had a much bolder, powerful sound & the delicacy of the Mk1 version was gone. This was bad news for my friend & he ended up selling the RM9. I listened to his system with the RM9 Mk1 & the RM9 Mk2 & I concured with him - the RM9 Mk1 was a much better tube amp. And, Mk1 version was powerful enough to drive his PBN Montana speakers.
Bombaywalla, This is the case with many people who have their equipment upgraded to a MKII or upgraded (modified) by one of the many people who advertise mods. There is always a trade off and the original is often the best.
Bombaywalla, This is the case with many people who have their equipment upgraded to a MKII or upgraded (modified) by one of the many people who advertise mods. There is always a trsde off and the original is often the best.
In this case, when they're talking about the MKI to MKII upgrade by Roger, the mod / upgrade is being done by the original designer himself.
Does this "upgrade" consist of coupling capacitor changes? They can often result in dramatic differences in the sound which may or may not be an improvement. Are the modifications more than just capacitor replacement?I`ve heard some mods that lead to msrked improvement.
This should explain the differences in the various versions of the RM-9. Second post is from Roger:

Coupling capacitors were not replaced, nor do I feel these would make a difference in Roger's circuit. In addition, to me the sound did not change all that much between the versions. That said I feel the RM-10 MkII is an overall better amp than either the MkI or MkII version of the RM-9 if you can live with 35 watts.
nice choice Jim, congrats. My only suggestion on your continued enjoyment of the amp would be buy your replacement tubes from RAM Labs/Roger - saves alot of aggravation & you'll always enjoy great sound for many years to come. cheers & enjoy!
Thanks very much Pehare. Yes, Roger has been extremely nice and helpful. I only wish I could get him to explain everything he knows to me, but that might be a long phone call.

I believe it has the original tubes and the transconductance on my TV-7 is 39-41 for all 8 tubes! I also got a set of RAM KT-88s but haven't tried them.

I probably will upgrade to a MK-II at one point, after I've gotten extremely familiar with the Mk-I. Roger said he'd just sell me the parts and let me install them. That way I can switch back if I want.