Hi, all. I'd appreciate some informed opinion.

I'm looking for a solution to a dead amplifier in my Infinity BU-120
sub. First, read these reviews - what an eye opener!

http://ecoustics.audioreview.com/psc...6_2741crx.aspx

The Infinity amp. is a "POS". Fortunately, I have very little invested
in my unit. The amp. has been scrapped for spare parts (mains
transformer, terminals, that's about it - the rest is junk.) I've
screwed a board over the hole (painted matte black) and mounted
regular speaker terminals on it so it's now a passive unit - looks
good and sounds very good, too!

It's now running off one half of a Yamaha M4 with a 50 Hz LP filter (a
bit of a waste of an M4 but I had it lying around.) Now I've got
plans for the M4, i.e. for a proper stereo system, so I need a
dedicated sub amplifier recommendation. I would prefer linear to
Class D.

Here's are my thoughts to date:
1. Find a cheap surplus stereo receiver and use 1/2 of that (rather
low powered at 20 - 25 watts but I have another passive sub for the
other channel so I could get 50 watts, or so. The idea works, did it
a couple of years ago.)
2. ditto, integrated amplifier (might get up to 100 watts, but likely
not cheaply.)
3. Find a used s/s monobloc amplifier (From where? What type? Cost?)
4. Build a custom s/s monobloc from a 100 watt linear power module ( I
have the technical skills and resources, also likely cheap enough -
but a bit time consuming.)
5. Find another, better quality Class D sub. amplifier. (From where?
What brand? Cost?)
6. Other?

Thanks for all replies.

Cheers,

Roger

MCM Electronics sells replacement subwoofer amp plates / modules. Can't say
if they are any good, or whether the price is right. Can't be too much worse
than what you had, though.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Engineer" wrote in message
...
Hi, all. I'd appreciate some informed opinion.

I'm looking for a solution to a dead amplifier in my Infinity BU-120
sub. First, read these reviews - what an eye opener!


http://ecoustics.audioreview.com/psc...6_2741crx.aspx

The Infinity amp. is a "POS". Fortunately, I have very little invested
in my unit. The amp. has been scrapped for spare parts (mains
transformer, terminals, that's about it - the rest is junk.) I've
screwed a board over the hole (painted matte black) and mounted
regular speaker terminals on it so it's now a passive unit - looks
good and sounds very good, too!

It's now running off one half of a Yamaha M4 with a 50 Hz LP filter (a
bit of a waste of an M4 but I had it lying around.) Now I've got
plans for the M4, i.e. for a proper stereo system, so I need a
dedicated sub amplifier recommendation. I would prefer linear to
Class D.

Here's are my thoughts to date:
1. Find a cheap surplus stereo receiver and use 1/2 of that (rather
low powered at 20 - 25 watts but I have another passive sub for the
other channel so I could get 50 watts, or so. The idea works, did it
a couple of years ago.)
2. ditto, integrated amplifier (might get up to 100 watts, but likely
not cheaply.)
3. Find a used s/s monobloc amplifier (From where? What type? Cost?)
4. Build a custom s/s monobloc from a 100 watt linear power module ( I
have the technical skills and resources, also likely cheap enough -
but a bit time consuming.)
5. Find another, better quality Class D sub. amplifier. (From where?
What brand? Cost?)
6. Other?

Thanks for all replies.

Cheers,

Roger

"Engineer" wrote in message
...
Hi, all. I'd appreciate some informed opinion.

I'm looking for a solution to a dead amplifier in my Infinity BU-120
sub. First, read these reviews - what an eye opener!


http://ecoustics.audioreview.com/psc...6_2741crx.aspx

The Infinity amp. is a "POS". Fortunately, I have very little invested
in my unit. The amp. has been scrapped for spare parts (mains
transformer, terminals, that's about it - the rest is junk.) I've
screwed a board over the hole (painted matte black) and mounted
regular speaker terminals on it so it's now a passive unit - looks
good and sounds very good, too!


Try www.adireaudio.com and look at their subwoofer amps. Anything you could
want in terms of power. I have one in my own sub and it's done very well
for me.

It's now running off one half of a Yamaha M4 with a 50 Hz LP filter (a
bit of a waste of an M4 but I had it lying around.) Now I've got
plans for the M4, i.e. for a proper stereo system, so I need a
dedicated sub amplifier recommendation. I would prefer linear to
Class D.

Here's are my thoughts to date:
1. Find a cheap surplus stereo receiver and use 1/2 of that (rather
low powered at 20 - 25 watts but I have another passive sub for the
other channel so I could get 50 watts, or so. The idea works, did it
a couple of years ago.)
2. ditto, integrated amplifier (might get up to 100 watts, but likely
not cheaply.)
3. Find a used s/s monobloc amplifier (From where? What type? Cost?)
4. Build a custom s/s monobloc from a 100 watt linear power module ( I
have the technical skills and resources, also likely cheap enough -
but a bit time consuming.)
5. Find another, better quality Class D sub. amplifier. (From where?
What brand? Cost?)
6. Other?

Thanks for all replies.

Cheers,

Roger

"Michael McKelvy" wrote in message
ink.net...

"Engineer" wrote in message
...
Hi, all. I'd appreciate some informed opinion.

I'm looking for a solution to a dead amplifier in my Infinity
BU-120
sub. First, read these reviews - what an eye opener!



http://ecoustics.audioreview.com/psc...6_2741crx.aspx

The Infinity amp. is a "POS". Fortunately, I have very little
invested
in my unit. The amp. has been scrapped for spare parts (mains
transformer, terminals, that's about it - the rest is junk.) I've
screwed a board over the hole (painted matte black) and mounted
regular speaker terminals on it so it's now a passive unit - looks
good and sounds very good, too!


Try www.adireaudio.com and look at their subwoofer amps. Anything
you could
want in terms of power. I have one in my own sub and it's done very
well
for me.

A very good lead, thanks. Great products. The AVA250 is just what I
want but a bit pricey for us Canadians after shipping, an X/C rate of
75 cents US per CDN$, then our 15% sales tax, plus an insulting $5
sales tax collection charge by the bandits at "Revenue Canada"!
Starting at US$179.00, I make that close to CDN$300 "FOB my house"..
so, still looking!

BTW, the dead "POS" Infinity amplfier has an LM2324N quad Op Amp, so
that might end up as the front end of a home brewed sub-monobloc
(audio gain plus multipole LP filter.) Same for the power supply,
although it's a bit small - I estimate the transformer to be barely 50
watts continuous at 30-0-30 VAC, say +/- 40 VDC output. Assuming the
PA module can swing the output +/- 35 volts that gives about 75 watts
into 8 ohms (not continuous, either.) I think the Infinity driver
(not a "POS", incidently, quite a nice 12 inch unit) may be 6 ohms (it
has 4.8 ohms DC resistance), so I might just get 100 watts (not
continuous).. so, still thinking, too...

Cheers,

Roger
(snip)

Check the web for "Parts Express". They have some good-looking plate
amplifiers that you could just screw over the hole.

Engineer wrote:

Hi, all. I'd appreciate some informed opinion.

I'm looking for a solution to a dead amplifier in my Infinity BU-120
sub. First, read these reviews - what an eye opener!

http://ecoustics.audioreview.com/psc...ers/Subwoofers
BU-120/PRD_119596_2741crx.aspx

The Infinity amp. is a "POS". Fortunately, I have very little invested
in my unit. The amp. has been scrapped for spare parts (mains
transformer, terminals, that's about it - the rest is junk.) I've
screwed a board over the hole (painted matte black) and mounted
regular speaker terminals on it so it's now a passive unit - looks
good and sounds very good, too!

It's now running off one half of a Yamaha M4 with a 50 Hz LP filter (a
bit of a waste of an M4 but I had it lying around.) Now I've got
plans for the M4, i.e. for a proper stereo system, so I need a
dedicated sub amplifier recommendation. I would prefer linear to
Class D.

Here's are my thoughts to date:
1. Find a cheap surplus stereo receiver and use 1/2 of that (rather
low powered at 20 - 25 watts but I have another passive sub for the
other channel so I could get 50 watts, or so. The idea works, did it
a couple of years ago.)
2. ditto, integrated amplifier (might get up to 100 watts, but likely
not cheaply.)
3. Find a used s/s monobloc amplifier (From where? What type? Cost?)
4. Build a custom s/s monobloc from a 100 watt linear power module ( I
have the technical skills and resources, also likely cheap enough -
but a bit time consuming.)
5. Find another, better quality Class D sub. amplifier. (From where?
What brand? Cost?)
6. Other?

Thanks for all replies.

Cheers,

Roger

"Stu R" wrote in message
news
Check the web for "Parts Express". They have some good-looking
plate
amplifiers that you could just screw over the hole.

Stu, I think you hit the jackpot! The 300-804 is exactly what I want
and the landed price in Canada seems to be a just about affordable at
CDN$190, or so. It also does more that I could ever design, build and
test in several W/E's, with more protection than my present Yamaha M4
set up!

Many thanks,

Cheers,

Roger

(snip)

"Engineer" wrote in message
...
"Stu R" wrote in message
news
Check the web for "Parts Express". They have some good-looking
plate
amplifiers that you could just screw over the hole.

Stu, I think you hit the jackpot! The 300-804 is exactly what I
want
and the landed price in Canada seems to be a just about affordable
at
CDN$190, or so. It also does more that I could ever design, build
and
test in several W/E's, with more protection than my present Yamaha
M4
set up!

Many thanks,

Cheers,

Roger

(snip)

Damn, I was wrong! "Partsexpress" only have free shipping in the US.
I can't believe this c**p! Where's free trade when you need it? I can
more or less live with a 75 cent dollar since most Canadians (but not
me!) have voted in governments over the years that are determined to
keep us some 25% less productive than the Americans - even while
getting free continental defense but still bitching about American
imperialism and defining ourselves as "not-American. But to have to
pay over CDN$220 (landed) for a unit well priced at US$120 F.O.B.
anywhere in the US is a bloody disgrace.

Cheers, well almost...

Roger