Best SQ amp in a small package?

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Small package SQ amps...

Hi all,

You may have been thinking of Brax or Helix brand amps. They used to be sold through http://www.theautophile.com, but I'm not so sure if they're still offering the amps.

Very thin (like 1") with very nice SQ.

I also remember a positive review of the Alpine PDX series... small amps, but I think they're something like 2 inches thick. I think they also mentioned a little lightness on the very low end.

From the old school, I have always liked the old school a/d/s/ amps. I had a system back in the late 80s that had a pair of PQ20s (one on corners, one bridged to subs) that to this day is the cleanest sounding system I've done short of my last system (Dynaudio speakers with a McIntosh amp... that was *real* nirvana, but expensive.)

You also can't go wrong with the old school A series amps from PPI... the A404 was an awesome performer and wasn't very large at all.
 
ppia600 said:
Buy a ppi pro mos 12 or pro mos 25 and run all speakers on it with some good external crossovers.

Yeah, I'm quoting myself... 😱

If you find a ppi pro mos 12 or a 25 and use the following:

2 6 x 9 woofers with no tweeters, both connected with good chokes that will chop off most of upper mid and higher

2 mids with a good 12 db high pass passive crossover

2 1" fabric dome tweeters with good 12db high pass crossover that takes over where the mid crossover left off

(you will need to design the crossovers yourself, I believe parts express sells all of the chokes, caps, etc. and even gives the formulas for determining values to build your own crossovers)

1-bridge the two woofers at 2 ohm (be sure to use the chokes/inductors)
2-run the mids and tweeters in stereo with your passive crossovers

-The crossovers will prevent the respective drivers from attempting to play the incorrect frequency band and ease the load on the amp. The amp is already designed to run at 2 ohms mono, it won't die. I'd get the pro mos 25 if you can fit it, but the 12 is tiny and pretty potent. They both are excellent for sq
 
I don't know how they do it, but Zapco & Memphis make some miniscule amps for their power & quality

Can't vouch for Memphis, but Zapco used to boast outrageous (>90%) efficiencies for some of their power supplies back in the 80's. As a contrast, Rockfords typical of that era were quoted as around 50%. I can only assume they have maintained or improved on the performance.

The Z50 4 channel was a neat little 12.5W x 4. If it sounds like the rest of their stuff did at that time, it's impeccable for SQ. I doubt that'd be sufficient power, though.

I haven't tried any of their stuff since they went balanced, but their balanced input would take a speaker-level head unit signal directly with the possible addition of a resistor or two. Their AG series amps are fairly thin, but were entry-level. Maybe someone has had experience with these?

A little off original question but how do those Mac amps sound

It would require a heretic to drive a McIntosh with a head unit's built-in amp. Of course, an angry mob would ensue...

I understand your comment about the Alpine's sound, but IMHO speaker choice and treatment should have a more profound effect on liveliness than the amp -as long as it's a decent amp.
OTOH, if speaker choice, enclosure, placement, etc are excellent, then detailed differences in amp will show up well. Hmm, digression. It must be getting late.

Tim
 
Blaupunkt 'Plastic' Amplifiers

Something a little newer would be the blaupunkt 'plastic' amplifiers. You will occasionally find them for sale on ebay.

Here was one that was just sold for 50 bucks with a head unit:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140179207209

And another less powerfull one ending tomorrow:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160181580446

You can see in the first auction the plastic cover was removed. Inside is a tiny stereo amplifier you can fit almost anywhere. Plenty of power and clarity. I believe driven by the same Tripath chip thats in the 41hz Trupath amplifiers.
 
This is really interesting as my first thought was to build a T-amp for the car because I've been playing with one for the home for the last year and its incredible. This one is called Charlize made my DIYParadise. Just steller. Downside is its only 15-20W. I then thought about building the 41Hz Amp 9 for the car.

This all went out the window when I was completing repairs to a pre-amp for a friend. When I hooked it up to the Charlize without shielded cables I got incredible hum. I confirmed with the manufacturer that these T-amps put out a lot of RF. The car its going in has computer everything that are very sensitive to RF. So I nixed the idea.
 
I confirmed with the manufacturer that these T-amps put out a lot of RF. The car its going in has computer everything that are very sensitive to RF. So I nixed the idea.

How about a 12V DIY amp? The ADS PS5/PQ8/PH12 all ran discrete bridged amps right off 12V and performed quite well. A couple of other Mfr's have done respectable work with IC's.

Tim
 
I would love to build an amp. The one I mentioned runs off 12V as does the 41Hz amps. Just the RF issue.

You know of a great kit?

I found an update on the stock radio head unit. For some bizarre reason it looks like they put a high pass filter on the rear speakers. Some owners have complained they can't get any bass back there even with a new amp. Here's the thread with measurements.

Mini Stock radio frequency response
 
You know of a great kit?

Unfortunately, no. Some one else may. If not, you're in the right place to come up with a new one.

I can't see the graphs, as I can't log in to the site. Can you post the rear in the updated log format?

The filtering could be an equalization of cabin gain, or maybe there isn't sufficient volume behind the rear speakers to get them to go low. Filtering could make more efficient use of the amp and be less likely to damage a speaker. Is it extreme, or just the last couple of octaves?

The response/filter could also be volume-dependent. By 0dB sine wave, was he implying the test was without attenuation, with the volume pegged? The poster didn't mention at what actual voltage he was testing. Was it from the speaker outputs or the preamp? It wouldn't be surprising to see different graphs at different volume settings, and different graphs from line out and speaker outputs.

Did I miss it, or is that a question worth asking?

Tim
 
I just mentioned the response as a side note in conquering this project correctly. I downloaded the graphs. One with 0dB and the other with voltage. Here they are.
 

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Mac SQ

Hi Phrarod,

It's hard to find the words to describe how sublime the sound is from my MC440... In combination with my Dynaudio drivers, the sound is impeccable. The most surprising thing for me was the absolute absence of noise... truly an inky blackness from which the sound emerges...

OMIGOD... I'm sounding like the Sterophile guys. Sorry, lost my head for a minute. 😉

smiles,
Jamie

phrarod said:
A little off original question but how do those Mac amps sound? I never cared for the home amps as I thought they sounded too warm and veiled but a car is of course a completely different story.
 
Wow Jamie. Impressive review. I looked it up. Tons of incredible reviews. There's on eBay but the person wants $800 for a 10 yo amp. Anyway, its huge. Good to file away though as a special amp.

One review said the only amp he heard that was better was the Tube blue driver amp. Have you ever heard those?

Now back to our scheduled broadcast of small amps with great SQ....
 
I just mentioned the response as a side note in conquering this project correctly. I downloaded the graphs. One with 0dB and the other with voltage.[/

It's an interesting point, and a good lesson for anyone who is working with portions of a factory system.

The voltage graph shows over 7 volts for >100Hz. That's speaker level, and certainly near maximum clean output. I assume that the preamp output has a similar response.

The question is why is it so? Are the rear speaker locations really not suited to reproduce low end? If so, that should influence speaker selection when upgrading. And if so, can the locations be treated so as to increase low end response?


Tim
 
Hi Tim. Everyone in the MINI community is wondering about that one. I guess MINI figures you won't be able to get more than mid-bass out of that location with 6x9 speakers. The CDTs everyone likes claim they only go down to 45Hz and up to 4K CDT CL69

Still if you treat the area some decent bass sound come out shouldn't it? Nothing like a 10-12" in an enclosure but decent bass fill?

It would be nice to figure out how to defeat the HU and use roll your own x-over..
 
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