41Hz Audio offer nice Amp kits on their website. They have three amps with different power output ratings. I am wondering whether there are differences in sound quality. Did anyone compare these amps (in particular the amp1 and amp3, which are interesting for my purposes)?
Mick
Mick
I think the "big" sound referred to describes the quality, as much as the quantity of the sound from the Amp3. I've been testing my Amp3 on Gale 401As, that had a real reputation as an amp eater. 4ohms, ~82-84dB. The Amp3 drives it beautifully, up to ~90dB. Plenty loud in a smallish room. Up to this level, the Amp3 really sounds very even, composed and in control.
The Amp3 was brought over to a friend's and hooked up to Polk Signature series 2.3TL. 55" tall; bass to 25Hz. You should have seen the his face when the Amp3 produced really deep, controlled bass. Better, IMO than his class-A MF amp. At 90 dB/m sensitivity, the Amp3 was probably driving it to ~95-100dB / 1m.
The Sonic Impact T-amp I was playing around with probably clipped at 10% of the power output of the Amp3. Although technically it has 50% of the Amp3's power, the power supply caps, input cap, output inductor, etc limit the T-amp severely. Personally I was quite surprised myself as to how much sound a clean 4-8W can produce!
The Amp3 was brought over to a friend's and hooked up to Polk Signature series 2.3TL. 55" tall; bass to 25Hz. You should have seen the his face when the Amp3 produced really deep, controlled bass. Better, IMO than his class-A MF amp. At 90 dB/m sensitivity, the Amp3 was probably driving it to ~95-100dB / 1m.
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The Sonic Impact T-amp I was playing around with probably clipped at 10% of the power output of the Amp3. Although technically it has 50% of the Amp3's power, the power supply caps, input cap, output inductor, etc limit the T-amp severely. Personally I was quite surprised myself as to how much sound a clean 4-8W can produce!
yeah it's very enlightening to hear just how good these little guys (SI and Amp 3) sound while having fairly low output power! i had the chance to hook up a stock SI to some NHT 3.3's (they are 6ohm nominal which is what the stock output filter was designed for) and the sound quality (even using an ipod with uncompressed music as a source) and bass response was equal to, if not better than, the home theater receiver that was originally hooked up to. it couldn't drive the 3.3's as loud as the receiver but it was plenty loud even in the fairly large room. this was at an aes meeting with the amp hooked up behind the counter so everyone thought the HT receiver was the amp being used, and after we listened the SI was brought out from behind the counter and everyone looked a little stunned 
I have been recently comparing am Amp3 with my linn. Room 10m x 6m x 2.5m, mainly hard surfaces. More than adequate volume for me using an 88db FR speaker, smallish BR box. Todays quick test was running left channel through amp3, right channel through linn using the linn preamp section and swinging balance control. Unfortunately not mono signal, so not an exactly equal test. Thinking so far is that not much in it, linn may be very slightly better (so it should be at the price), but Amp3 far from disgraced with these speakers. Difficult to tell fine nuances with this setup. Will refine system and use better (and more difficult to drive) speakers sometime in the future
Amp3 much better than an oldish Pioneer 36w SS I have on hand using same speakers.
I would be interested in results of directly comparing Amps 2 and 3 also. Certainly I think the Amp3 very good value and well worth building, even as a learning exercise.
SMD components no problem, but main chip has very fine legs and I had difficulty with placing that accurately.
Amp3 much better than an oldish Pioneer 36w SS I have on hand using same speakers.
I would be interested in results of directly comparing Amps 2 and 3 also. Certainly I think the Amp3 very good value and well worth building, even as a learning exercise.
SMD components no problem, but main chip has very fine legs and I had difficulty with placing that accurately.
amp 1 and amp 3 comparison
I have a little setup with an amp 3 powered by a worked over SMPS. I can vouch for its qualities and power in relation to the SI which I also have. The SI has been extensively tweaked but the amp 3 only has quality input coupling caps added. This is no contest sonically.
As for the amp 1, I helped a friend by doing all the surface mount stuff for him. When he completes it I will do a direct comparison and report here.
Roger
I have a little setup with an amp 3 powered by a worked over SMPS. I can vouch for its qualities and power in relation to the SI which I also have. The SI has been extensively tweaked but the amp 3 only has quality input coupling caps added. This is no contest sonically.
As for the amp 1, I helped a friend by doing all the surface mount stuff for him. When he completes it I will do a direct comparison and report here.
Roger
AMP1 & AMP3 Comparison
Hi, I have posted an AMP1 vs AMP3 comparison on the 41hz forum: http://www.41hz.com/Forums/topic.asp?TOPIC_ID=218
I'm planning to do another follow-up on this. What I can say without any doubt is that you have to burn in the AMP1 for an extremely long time.
I have built all kinds of amps....including TUBE amps, and I have never come along a project that has such a big difference between "fresh" and burnt-in as the AMP1.
Fresh its frankly quite mediocre. A bit shrill and lacking bass. The only positive thing to say about it "out-of-the-box" is that the soundstage is wide...
You will have to spend quite a few hundred hours to get it sparkling...bur when it does, it actually surpasses the AMP3 in sound quality. After a while it goes from Shrill to clear.... (Its like listening to a pair of Fostex fullrangers new, and after a couple hundred hours).
Hi, I have posted an AMP1 vs AMP3 comparison on the 41hz forum: http://www.41hz.com/Forums/topic.asp?TOPIC_ID=218
I'm planning to do another follow-up on this. What I can say without any doubt is that you have to burn in the AMP1 for an extremely long time.
I have built all kinds of amps....including TUBE amps, and I have never come along a project that has such a big difference between "fresh" and burnt-in as the AMP1.
Fresh its frankly quite mediocre. A bit shrill and lacking bass. The only positive thing to say about it "out-of-the-box" is that the soundstage is wide...
You will have to spend quite a few hundred hours to get it sparkling...bur when it does, it actually surpasses the AMP3 in sound quality. After a while it goes from Shrill to clear.... (Its like listening to a pair of Fostex fullrangers new, and after a couple hundred hours).
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