fruggiedesh
New Member
I understand that there are speakers out there with a much more complete low end response. I am simply comparing the sounds of the SU-V9/M-60 using the same speakers.
Information on Yamaha Components
- Thread starter fruggiedesh
- Start date
I understand that there are speakers out there with a much more complete low end response. I am simply comparing the sounds of the SU-V9/M-60 using the same speakers.
i'm assuming you're doing the comparison with all tone controls set to "flat"?
I have a Yamaha M-4 amp recently refurbished by Avionic and can only say I'm blown away by how good it sounds. The bass is authoritative, crisp highs, and I have a lot of dynamic range. I also love how well it behaves with the different speakers I have, which range from a 4 ohm Spica TC-50 to a power hungry Theil 04a and a set of Rat Shack Optimus 6 or something.
I got the M-4 after first getting a Yamaha A-1 integrated, which also blew me away. Especially because despite its age (from the late 1970s), blew away the Nakamichi RE-2 receiver (similarly powered) that it was replacing.
Right now I'm running the A-1 as my preamp for the M-4. I am doing this mostly as a stopgap measure until I save enough to get a preamp. However, the sound of the A-1's phono section is superb, so I'm not sure what I'll decide.
Interestingly, the A-1 (used as a preamp) runs hotter than my M-4, though not too hot to the touch by any measure. I'm speculating that this is because the M-4 has been recapped and cleaned well, whereas all I've done to the A-1 is blow out the insides with compressed air.
Perhaps some of you can refute or better explain the temp. differences ...
I got the M-4 after first getting a Yamaha A-1 integrated, which also blew me away. Especially because despite its age (from the late 1970s), blew away the Nakamichi RE-2 receiver (similarly powered) that it was replacing.
Right now I'm running the A-1 as my preamp for the M-4. I am doing this mostly as a stopgap measure until I save enough to get a preamp. However, the sound of the A-1's phono section is superb, so I'm not sure what I'll decide.
Interestingly, the A-1 (used as a preamp) runs hotter than my M-4, though not too hot to the touch by any measure. I'm speculating that this is because the M-4 has been recapped and cleaned well, whereas all I've done to the A-1 is blow out the insides with compressed air.
Perhaps some of you can refute or better explain the temp. differences ...
fruggiedesh
New Member
Well until I get my hands on a C-2x, I'm still using my SU-V9 as a pre. I only ever use it with the DC setting.
NumbDiver
Super Member
After owning much of the Yamaha gear, my preferences without spending huge $$$ are:
-Vfet B-2
-C-2x (it's really THAT much better than the others, well worth waiting for).
-CT-7000, T-2, T-85 (or T-2x if you can find one), T-1. In that order.
My Yammy gear is mostly gone now, as I'm back in tubes. But I hung onto a B-2 anyway. Somedays I miss the C-2x as well.
-Vfet B-2
-C-2x (it's really THAT much better than the others, well worth waiting for).
-CT-7000, T-2, T-85 (or T-2x if you can find one), T-1. In that order.
My Yammy gear is mostly gone now, as I'm back in tubes. But I hung onto a B-2 anyway. Somedays I miss the C-2x as well.
islapapa
Active Member
Why should one not run a M-85 in auto class A for extended periods of time? Is it not properly designed, or is this true with all class A amps?
Thanks,
Steve
Well, I think the short answer is that it should have more heatsinking for the Auto A purposes. The extra heat has necessitated some (many?) repairs of these amps, and IIRC a few AKers know firsthand about this. If you turn off the amp when you're not using it, and perhaps turn off Auto A when during loud listening sessions, that will certainly help, but unfortunately I don't have any firm knowledge of how much Auto A an M-85 can take before the long term damage starts to show. I was running one on a concrete floor with nothing stacked on top for several hours at a time with no apparent issues, but that was only for a few weeks. Generally I'm pretty trusting in the ruggedness of 20+ year-old amps that have made it this far, but sometimes you don't know how much use a second-hand amp has really had and whether it's been challenged enough to bring out such hidden reliability issues.
the-real-mandak
Super Member
IIRC Yamaha said something about only using the auto class A for critical listning, witch would be logic anyway - save power be green ;-)
fruggiedesh: get youself a C-60/65 while you wait for a C-2x, it can be some time before one shows up at a price you're willing to pay.
fruggiedesh: get youself a C-60/65 while you wait for a C-2x, it can be some time before one shows up at a price you're willing to pay.
SoCal Sam
Lunatic Member
Hot running amps with plastic clad output transistors is trouble waiting to happen. IMO, better to avoid them and get a cool running amps with metal die T-03 output transistors like the PC2002M.
i agree with you, TO-3 is generally better in a tough thermal situation. however, if running hot gets me noticeably better sound, TO-3 or not, then i'd want to try to find a way to deal with it, at least within reason. case in point: my BX-1s. i'm going to have to talk with Avionic to see what he did fan-wise with the pair he worked as these sound fantastic but do run scaldingly hot.
Given what I'm seeing after being inside several of my M-80's, these issues are related more to the corrosive properties of the cap glue Yamaha used breaking down and eating through the component leads. I've already replaced a big grip (handful) of parts in 2 of these, only one of them actually had an issue and it was a "squiffy" 220uf 6.3V rubycon electrolytic cap drowning in the old adhesive. 4 caps, 2 zeners, 4-6 1/8w resistors and cleaning up the ground bus bar on most.
None of these caps look or check out as heat damaged. I've seen the same thing in some of the pre-amps with the glue used to hold down small heat-sinks where surrounding components have either gone off spec or broken down due to the corrosion. I've actually had to remove some copper ground bus bars and grind & polish them with a dremel.
specialidiot
Break Glass, Smoke Lucky
numbdiver nailed it.
I've ran a lot of gear through my racks but my B-2 and C-2x still remain.
I've ran a lot of gear through my racks but my B-2 and C-2x still remain.
islapapa
Active Member
Thanks for valuable insight. My C-85 pre was giving me a little trouble, and while looking around I noticed that two resistors in front of the small heat-sinks were encapsulated in a brownish shellac type substance. I chipped it off the resistors with a chopstick - they "looked" undamaged. Is this cap glue? To prevent future damage, should I be looking for similar areas in my M-85? What to do?? :scratch2:
Many Thanks,
Steve
Installed one of these Airpax on the heatsink and a jack on the rear panel.
http://www.newark.com/airpax/67f040/thermostat/dp/79K1558?MER=PPSO_N_C_EverywhereElse_None
Attachments
Heatsink/capglue; yes, it turns hard, brittle, and corrosive. That, or it holds moisture in that causes the corrosion. I had to replace those two resistors and the two 100pf/100V polypropylene caps as well in a C-80. I'm going to start going through things before they find new homes. I've several C-80/C-85, etc. that work fine but will get the attention they deserve.
I've been inside two of my M-80's so far and both have cap glue issues that required replacement of the components outlined earlier. Look at the main horizontal board, near the front, centerline. It's split L/R channel.
Soldering on some of these boards is not DIY unless you're really good with an iron. It was said elsewhere repair of the M-80 wasn't DIY, but mine was fairly easy to find, just one squiffy cap and it was one within the glue perimeter. 2 weeks of soldering class during my 11 month electronics training as a microwave radio repairman 30 years ago made me slightly dangerous and braver than I ought to be.
