Monoblock amps - Altec A340A's or McIntosh MC30's

**bhmav8r** · August 3rd, 2014, 06:29 PM

Any one have experience with both of these?

I have an opportunity to buy either.

They will run my 19's and Khorns. McIntosh MA6500 currently, but looking for tubes.

Thanks in advance.

**jmarkwart** · August 4th, 2014, 10:35 AM

I used to use a pair of MC30s on A7s in a home setting. They were very clean sounding (ala S/S) with no audible hum plus excellent speed, dynamics and freq extension. The design is fairly bullet proof and a pair of output tubes seem to never wear out due to their low current biasing. Hard to go wrong with a pair of these or a MC240 on Altecs.
Jeff

GM · August 4th, 2014, 02:44 PM

No useful experience with the A340, but my then 'clean, one owner' MC30s sounded a bit 'dark' compared to a MC275, so traded up as soon as I could afford it. For all I knew way back then though, it could have been 'tuned' that way intentionally by the original owner and of course the dealer wasn't going to say anything to lose a potential sale! That said, decades later someone on the Sound Practices List [joelist] made the same observation, so maybe not.

GM

**604man** · August 4th, 2014, 04:36 PM

The Mcintosh amps employ A bifilar output transformer with lots of NFB and the
output tubes are run at near class "B" operation....Quite novel in design to
get the low distortion ,wide band with specs silk-screened on the side of that
chrome chassis :-)

Looking at the Altec A340 circuit, it's standard pentode output, most likely class A/B......

The trend in tubes today is class A triodes..............GC

**tomt** · August 4th, 2014, 07:20 PM

Originally Posted by bhmav8r

I have an opportunity to buy either.

why limit yourself?

get both.

**604man** · August 5th, 2014, 02:52 AM

If you have silly money to spend, You might consider the Brook amps.
PWK's favorite... go here.
retro vintage modern hi-fi: BROOK Electronics 12A one of PWK's favorites

You could DIY , There is A zillion circuits on the web........GC

**wws944** · August 10th, 2014, 05:08 PM

My late audiophile uncle ran his (now my) Altec 820s with MC30s for many years. He eventually bought a SS MC2100 (also now mine) and never switched back. Liked the extra power reserve. He re-purposed the MC30s for a different system.

I keep looking at those old Altec theater amps on ebay, but just can't get past the high distortion specs in the bass. As 604man said back a few posts, the circuit topology in them doesn't seem that special.

**tomt** · August 14th, 2014, 04:28 AM

Originally Posted by wws944

I keep looking at those old Altec theater amps on ebay, .

which ones/models?

**604man** · August 14th, 2014, 10:33 PM

I think it's unrealistic that one amp will cover all bases . I think tubes
sound best at low to medium volume levels , which is my preference
these days, But I still like SS for the punch......GC

**wws944** · August 16th, 2014, 01:12 AM

Originally Posted by tomt

which ones/models?

Looking at the occasional 1568A and 1569A. For example the 1569A is rated "80 watts at less than 2% THD from 60-20000 cps" and "80 watts at less than 5% THD from 40-20000 cps". Those seem more like old PA amp specs than home hi-fi. But then, I have never heard a set in a home environment. Just as an occasional movie theater patron, etc.