I have an aging Dynaco stereo power amp. 230 RMS watts @ 8 ohms, 20-20KHz,
both channels driven, etc., etc.

I'm looking for a reasonable cost replacement for it, of at least 200 RMS
watts @ 8 ohms per channel. Preferably in the $500 or less neighborhood.

The amp is often moved and used outdoors, so weight is of concern to me.
The Dynaco weighs 54 pounds and I'd definitely like to do better than that
next time. :-)

Anyone know of a reliable amp, capable of taking an occasional joke (shorted
speaker, etc.), that would fit that bill?

Thanks very much!
Bruce.

"Bruce Chastain" wrote in message


I have an aging Dynaco stereo power amp. 230 RMS watts @ 8 ohms,
20-20KHz, both channels driven, etc., etc.

Dyna 400 family (400, 410, 416, etc.) right?

I'm looking for a reasonable cost replacement for it, of at least 200
RMS watts @ 8 ohms per channel. Preferably in the $500 or less
neighborhood.

You might want to visit your local professional audio/music store type
place. Guitar Center is an example of a national chain of stores of this
kind. Look at offerings from QSC, Crown, and maybe Mackie.

The amp is often moved and used outdoors, so weight is of concern to
me. The Dynaco weighs 54 pounds and I'd definitely like to do better
than that next time. :-)

The Dyna 400 series didn't use the most efficient power transformers and
heat sinks, so you should be able to shave off maybe 15 pounds more-or-less,
which will make a big difference in your perceptions when you lug it.
Built-in carry handles, which some of them have, help quite a bit.

Anyone know of a reliable amp, capable of taking an occasional joke
(shorted speaker, etc.), that would fit that bill?

The manufacturers I mentioned make amps that are as close to bulletproof as
they can make them, and they mostly succeed.

"Arny Krueger" wrote in message
...
Dyna 400 family (400, 410, 416, etc.) right?

Correct. The Stereo 400.

You might want to visit your local professional audio/music store type
place. Guitar Center is an example of a national chain of stores of this
kind. Look at offerings from QSC, Crown, and maybe Mackie.

Thanks for the pointers.

The Dyna 400 series didn't use the most efficient power transformers and
heat sinks, so you should be able to shave off maybe 15 pounds
more-or-less,
which will make a big difference in your perceptions when you lug it.

They sure didn't! I love the large heatsink as it generally doesn't require
a noisy fan regardless of the load. I got a big laugh from the manual that
cautions not to use it as a record rack! :-)

But the transformer is another matter. Massive and very, very heavy.

Thanks for the advice.

Bruce.

In article , "Bruce Chastain" wrote:
I have an aging Dynaco stereo power amp. 230 RMS watts @ 8 ohms, 20-20KHz,
both channels driven, etc., etc.

I'm looking for a reasonable cost replacement for it, of at least 200 RMS
watts @ 8 ohms per channel. Preferably in the $500 or less neighborhood.

The amp is often moved and used outdoors, so weight is of concern to me.
The Dynaco weighs 54 pounds and I'd definitely like to do better than that
next time. :-)

Well, that amp is likely to last some time. Amps are getting real cheap. Some of the professional
stuff especially. There is some Crown amps at Parts Express, 570 watts/ch @ 2 ohms,
for $300. Hows that. 25 lbs. Probably has a fan.

greg

"GregS" wrote in message
...
Well, that amp is likely to last some time. Amps are getting real cheap.
Some of the professional
stuff especially. There is some Crown amps at Parts Express, 570 watts/ch
@ 2 ohms,
for $300. Hows that. 25 lbs. Probably has a fan.

Very nice looking. Thanks for the pointer.

The only thing I don't like generally about the Crown amps, which would
prevent me from buying one, is that the power output is rated at 1 Khz,
rather than across the typical audio spectrum, say 20-20Khz. So I have no
idea if whether the amp response drops unacceptably or not when it's
cranked. I seriously doubt it, but never-the-less I can't tell from their
specs. Since I will be using it outdoors, how it performs under high load
is critical to me.

http://www.partsexpress.com/pdf/245-460d.pdf

I thought the FCC required amp makers to rate their amps that way, but I
guess that must not be true anymore.

But thanks for the reference.

Bruce.

"Bruce Chastain" wrote in message


"GregS" wrote in message
...
Well, that amp is likely to last some time. Amps are getting real
cheap. Some of the professional stuff especially. There is some
Crown amps at Parts Express, 570 watts/ch @ 2 ohms, for $300. Hows
that. 25 lbs. Probably has a fan.

Very nice looking. Thanks for the pointer.

The only thing I don't like generally about the Crown amps, which
would prevent me from buying one, is that the power output is rated
at 1 Khz, rather than across the typical audio spectrum, say
20-20Khz.

The spec sheets introduce a relevant parameter called "bandwidth power" and
then don't say what it is for any of the XLS series amplifiers.

So I have no idea if whether the amp response drops
unacceptably or not when it's cranked. I seriously doubt it, but
never-the-less I can't tell from their specs. Since I will be using
it outdoors, how it performs under high load is critical to me.

http://www.partsexpress.com/pdf/245-460d.pdf

I thought the FCC required amp makers to rate their amps that way,
but I guess that must not be true anymore.

Not a *consumer* product. That gets Crown off the hook for FTC ratings.

AFAIK other, non-price-leader Crown amplifier lines still have 20-20 KHz
ratings.

In article , "Bruce Chastain" wrote:
"GregS" wrote in message
...
Well, that amp is likely to last some time. Amps are getting real cheap.
Some of the professional
stuff especially. There is some Crown amps at Parts Express, 570 watts/ch
@ 2 ohms,
for $300. Hows that. 25 lbs. Probably has a fan.

Very nice looking. Thanks for the pointer.

The only thing I don't like generally about the Crown amps, which would
prevent me from buying one, is that the power output is rated at 1 Khz,
rather than across the typical audio spectrum, say 20-20Khz. So I have no
idea if whether the amp response drops unacceptably or not when it's
cranked. I seriously doubt it, but never-the-less I can't tell from their

I don't think they could last as a manufacturer, if they could not
put out when cranked. Thats what they were built for. If the max power
is much more than you need, the unit should also have not problem putting
out less watts. If you have some desire to generate rumbling at 20 Hz,
it will probably work anyway.

greg

"Arny Krueger" wrote in message
...
Yes, but both Crown and QSC have a lot more amps in their product lines.
Try
the two manufacturer's web sites.

Ok, spent quite a bit of time sorting through all that (and other sites).
As a general rule, the amps that provide the power/response specification
are well over my $500 target, usually $600-$900. Those that either don't
say or just rate it at 1KHz, are $300-$500.

Frankly I wouldn't worry about it. No doubt these amps put out less watts
at
20 KHz and 20 Hz than 1 KHz, but you can buy them big enough to put out
gobs
of power at the frequency extremes anyway.

I appreciate the advice, but I am worried about it, a lot. When I spend
that kind of money I'm not going to try to guess what the amp might be or
might not be doing. Either the specs tell me what I'm buying, or I have to
assume they're hiding something and I'm not interested. I'm not going to
spend that kind of money and then forever wonder what compromises I made.

And the price ranges I've found seem to certainly back that up. After
looking at a bunch of amps last night and this morning, the cost of amps
with that rating are about 50% higher. Obviously that rating must
complicate the design, and that rating doesn't come cheap.

So it's looking like I'm going to have to rethink my price target, and
significantly over $500 isn't in the budget at the moment.

Thanks for the help,
Bruce.

"GregS" wrote in message
...
I don't think they could last as a manufacturer, if they could not
put out when cranked. Thats what they were built for. If the max power
is much more than you need, the unit should also have not problem putting
out less watts. If you have some desire to generate rumbling at 20 Hz,
it will probably work anyway.

Thanks Greg, but I doubt most people couldn't easily tell the difference, so
that's why the specs are so critical when comparing performance. If the amp
can do the job the specs would reflect that, or I have to assume it probably
can't.

Bruce.

In article , "Bruce Chastain" wrote:
"GregS" wrote in message
...
I don't think they could last as a manufacturer, if they could not
put out when cranked. Thats what they were built for. If the max power
is much more than you need, the unit should also have not problem putting
out less watts. If you have some desire to generate rumbling at 20 Hz,
it will probably work anyway.

Thanks Greg, but I doubt most people couldn't easily tell the difference, so
that's why the specs are so critical when comparing performance. If the amp
can do the job the specs would reflect that, or I have to assume it probably
can't.

Most all the time, just derating the power will make everything fall into place.
If you can stand maybe a 10-15% reduction in the power spec., then all
should be fine. The distortion levels also fall dramatically. I assume both channels
are tested the same time, just like home amps, but I'm not 100% certain.

The XLS amps seem to have heftier power supplies than the old PowerBase series, in that the
power increases more in porportion to the load impedance. I have a couple of the PB2's.

greg

"Bruce Chastain" wrote in message
...
"Arny Krueger" wrote in message
...

Yes, but both Crown and QSC have a lot more amps in their product lines.
Try
the two manufacturer's web sites.

Ok, spent quite a bit of time sorting through all that (and other sites).
As a general rule, the amps that provide the power/response specification
are well over my $500 target, usually $600-$900. Those that either don't
say or just rate it at kHz, are $300-$500.

To some degree you get what you pay for.

Frankly I wouldn't worry about it. No doubt these amps put out less
watts at
20 KHz and 20 Hz than 1 KHz, but you can buy them big enough to put out
gobs
of power at the frequency extremes anyway.

I appreciate the advice, but I am worried about it, a lot.

If that's your final word then something will have to give.

When I spend
that kind of money I'm not going to try to guess what the amp might be or
might not be doing. Either the specs tell me what I'm buying, or I have
to
assume they're hiding something and I'm not interested. I'm not going to
spend that kind of money and then forever wonder what compromises I made.

Plan B - hit eBay and get the more expensive better-specified amp for a
price you can probably live with.

And the price ranges I've found seem to certainly back that up. After
looking at a bunch of amps last night and this morning, the cost of amps
with that rating are about 50% higher. Obviously that rating must
complicate the design, and that rating doesn't come cheap.

If you look at the schematics, the usual means used for producing a power
rating at low THD from 20 to 20K is to build a bigger amp and derate it a
few dB. IOW an amp with a 1 KHz rating of 120 watts becomes a 100 watt amp
from 20 to 20 KHz.

You can see suggestions of this at http://www.qscaudio.com/pdfs/cxspc.pdf .
The CX302V is rated at 200 watts 20-20 Khz and 250 watts at 1 KHz. This
includes the distortion in a 70 volt transformer so its safe to assume that
a transformerless amp will have a 20-20 KHz wattage that is even closer to
250 watts. The difference might be as little as 10% of the rated power.

So it's looking like I'm going to have to rethink my price target, and
significantly over $500 isn't in the budget at the moment.

Don't forget eBay. Been there, done that and with good results.

"Arny Krueger" wrote in message
...
If that's your final word then something will have to give.

Yep. :-)

Plan B - hit eBay and get the more expensive better-specified amp for a
price you can probably live with.

Good idea!! I'll give that a try!

I did find a reasonable candidate. The PLX 1202 Stereo Power Amplifier -
215W per Channel into 8 Ohms.

I was initially scared off because of the $800+ price, but
www.bhphotovideo.com sent me their "real" price by email and that turned out
to be less than $550! At least that's in the right neighborhood. Looks
like a very nice amp, and it's only 21 lbs!

Thanks for the help everyone!
Bruce.