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tube amp dilemma with ascents.

MartinLogan Owners (MLO)

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Les

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I am a new member here but have owned a Martin Logan theatre setup for a couple of years now.I have recently upgraded my power amp to the anthem P5 from the mca 5 and am exceptionally happy with the 5.1 but 2 channel just isn't doing it for me.[ Yes i know everyones issue ].The music is just too sterile. I am running a modified shanling cdt100 tube cd player and since it has a gain control want to input it directly into a tube amp and run it through my ascents for 2 channel.Recently i have tried an old dynaco 70 and like the sound but it is underpowered for the ascents and warm but not very accurate. I had a buddy bring over his original mac 275 and we thought it would be killer but it surprised us with its brightness. We swapped out the kt88's for some 6550's and it was a bit better but still very brite.
My question is this: have any of you done any experimenting with tube amps with the ascents to find the best combo.I am looking for that warmth and thickness but still want the accuracy.I listen to mainly blues and jazz.I do not have the space with my home theatre system to run monoblocks and do not know what size an amp i need in terms of power.My room is apprx 15x20.Any recommendation you guys may have would be much appreciated and if you want any info on what kind of equipment i am running for my home theatre that i am totally satisfied with , i would be pleased to discuss it and send you pics if you want.
Thanks in advance for your time and i look forward to your replies.
 

aliveatfive

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This is probably going to get very controversial, but here goes. I've heard Ascents (and their earlier incarnation relatives - the Sequels) with several kinds of Audio Research tubes. I currently own an ARC VT 100 III (just retubed with new Tung Sol 6550s) driving Ascent is. When I first used this amp with Sequel IIs I would describe the sound as you described the Mac 275 - somewhat dry with an overemphasized treble. This particular amp took months to break in. I also had to try different kinds of speaker cable to get satisfactory sound. I'm now using Transparent bi-wire MusicWave plus. All of the experimentation changed the sound to the point at which I am now happy with the set-up.

I found that a huge factor in the sound produced is the quality of the front end components. For example: A BAT VK51SE preamp made a huge difference compared to an ARC LS 22. An SME model 10 tt made a difference compared to a VPI HW19IV. An Esoteric DV50 made a big difference compared to a Theta Miles --- and so on. Front end components are very significant in perceived sound quality.

There are many ways you can experiment to change the sound. Good luck!
 

Sky Saw

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Hi Les, and welcome. I found that changing from a SS amp to a Blue Circle BC28 (hybrid amp) changed my Ascent-is from being merely incredibly accurate to breathing musical life into my listening room. The BC28 and Ascents is a great combination (holographic, incredible sense of air and space, timbral accuracy, plenty of power and drive, no grain, no hash, no excess midrange).

However, I am surprised that a Mac amp sounded bright on your system. Could your room be excessively live? If so, I suggest that you work on taming the room issues with wall coverings, furniture, etc. before trying system changes.
 

Spike

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The music is just too sterile. I am running a modified shanling cdt100 tube cd player and since it has a gain control want to input it directly into a tube amp and run it through my ascents for 2 channel.
1st suggestion is to audition a good/decent preamp in the mix. Sometimes the interface between the CD source directly connected to an amplifier may throw everything out of balance due to impedance mismatch.
I had a buddy bring over his original mac 275 and we thought it would be killer but it surprised us with its brightness.
I'm very surprised at this statement because this is atypical of Mac. this seems to suggest (impedance) imcompatibility between the CD source and the (MAC) amplifier.
We swapped out the kt88's for some 6550's and it was a bit better but still very brite.
The 6550 are not too much different than KT88. Try EL34 if you want warmth and bloom. Notice that I didn't use "thickness" since that term usually associates with sluggishness.
I do not have the space with my home theatre system to run monoblocks and do not know what size an amp i need in terms of power.My room is apprx 15x20.
What kind of space is available to you? Are you looking to replace the Anthem P5 with tube amp or to add the tube amp to augment the Anthem? Think bi-amping with tubes on the panels and solid-state on the woofers.
In general, Logans are pretty tough load for a tube amp due to the wide impedance swing. In my search, I had to look for a tube amp with beefy power supplies and with a choke on the input side in order to keep the input voltage rock steady given any demands from the speakers. My search lead me to the AES Sixpacs (little cousins of the Cary V12R) for my reQuests. I also auditioned a bunch of other tube amplifiers but the SixPacs proved to be the best match in my system. The SixPacs running in push-pull triode mode result in sweet, intoxicating midrange. You can take a look at my system #27 in the member system page if you'd like. Well that should give you something to start thinking about. Feel free to email me (or post here, preferred) and we can get more discussions about your system.

Spike
 
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Les

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tube amp dilemma with ascents

Geez guys after spending the last 4-5 years learning about ss and home theatre and now getting into tubes i feel like a complete idiot. There appears to be so much more knowledge required to produce a good sounding tube setup. I have no intention of selling any of my home theatre gear like the p5 and the avm20.I just want to plug and unplug speaker cables from theatre to 2 channel.Are you guys suggesting that i get a integrated tube amp instead of just an amp when my cd has remote gain control, i never thought that that may be a concern.Would running it direct always be an issue ? Like i had mentioned running mono blocks or an amp and pre are not an option for me due to space limitations so which would be better an integrated or direct as all i want to run through tubes is cd recordings.I know i won't achieve my quest on the first time around and will have to expand on better tube gear but what would you guys recommend in the 1000-1500 used range.I honestly don't think that my listening room has alot to do with what i was hearing from the mac.
Look forward to your replies
 

risabet

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I've got to agree with Spike. This is very likely an impedance mismatch with the CD player driving the amp directly. I've heard the 275 with other M-L's and they ain't thin sounding. Try the amp with a good pre-amp and hear what happens.
 
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