Yamaha MX-830 Power Amp

[WillMeyer]

I picked up two of the Yamaha MX830 power amps.

I've found very little info on them.
While they're rated at 170 watts rms in 8 ohms, my understanding is they run as a Class A amp up to a certain point, then switch to a Class B as the demand increases but I can't find anything specific confirming this nor at what point they switch.

Anyone have any knowledge on this amp?

It would really be nice if I could find a period test article on these.

 

[avionic]

Well here is the owners manual and service manual.
https://www.hifiengine.com/manual_library/yamaha/mx-830.shtml

 

[Mamrak1]

I found this post from 2003 if it helps you.

The Yamaha MX-830 came out in 1991 and along with the MX-630 and MX-1000u was the "big three" from Yamaha that year (not including the rare MX-2000 series).
It was rated at 170 watts per channel,has 3 sets of speaker outputs, and weighs in at 30lbs.
It has Yamahas HCA Hyperbolic Conversion Amplification which is suppose to be smoother from Class A to Class A/B transition than the earlier M series.I don't know how long it stays in Class A though,10-15 watts is my guess.It does not have the power meters like the M-85/MX-1000u.
I can't tell you how it sounds as I have never heard one but if the price is right (they retailed for $699.99 in 1992.)

 

[avionic]

not including the rare MX-2000 series

I've got one of those..

 

[Skywatcher]

I've got one of those..

Of course you do...

 

[avionic]

Anyone have any knowledge on this amp?

Yes..

 

[Skywatcher]

I picked up two of the Yamaha MX830 power amps.

I've found very little info on them.
While they're rated at 170 watts rms in 8 ohms, my understanding is they run as a Class A amp up to a certain point, then switch to a Class B as the demand increases but I can't find anything specific confirming this nor at what point they switch.

Anyone have any knowledge on this amp?

It would really be nice if I could find a period test article on these.

These have lots of power. I own one myself.

 

[avionic]

I picked up two of the Yamaha MX830 power amps.

Now get a C-70 or C-80/85 and hook up the amplifiers according to page 4 fig. 1 in the C-80 owners manual
http://sportsbil.com/yamaha/c-80-om.pdf

 

[Skywatcher]

Now get a C-70 or C-80/85 and hook up the amplifiers according to page 4 fig. 1 in the C-80 owners manual
http://sportsbil.com/yamaha/c-80-om.pdf

I have the matching CX-830 preamp that sounds just fine. And an SR-50 surround processor for the lower volume simulated "surround" that works quite well. The SR-50 has it's own amp for the rear speakers. It's only "powerful" enough for lower volume rear speaker use though. The "poor man's Yammy quad".

 

[Yamahalic]

High power amp to be sure, second in terms of raw power to the mighty MX-1000U. My old full-line brochure says, "HCA power, APS, High Dynamic Power, & Low Impedance Drive Capability)

 

[avionic]

I have the matching CX-830 preamp that sounds just fine.

Now get a C-70 or C-80/85 and hook up the amplifiers according to page 4 fig. 1 in the C-80 owners manual
http://sportsbil.com/yamaha/c-80-om.pdf

Inverted outputs are key.. For either 1 amp or 2 amps.

 

[WillMeyer]

Here's a pic of my system.
From the bottom-up, I have:
Two Yamaha MX-830 amps
Carver SD/A-360 CD player
Carver TDR-2400 Cassette
Carver CT-3 Preamp/Tuner
BSR EQ-3000
Adcom ACE-515 AC Enhancer.

One amp drives Boston T830's
The other amp has Infinity RS-8s on B, and Jamo Classic 8's on C

I run a Monitor Audio Radius 360HD sub.
I also have a Musical Fidelity clone Tube Buffer.

Nice sounding system; however, I'm not crazy about the CT-3 and will be replacing sometime in the near future.

I do want to say that I'm very impressed with the Yamaha power amps.
I was running three Carver TFM-15 power amps, I like the 2 MX-830s better.
The Carver amps are now on the storage shelf for spares.

 

[Electone]

Inverted outputs are key.. For either 1 amp or 2 amps.

I've got to try this with my C70 and M4.