This weekend I compared my BrianGT gainclone (standard kit version1) to my brother's Arcam A85. His amp cost £850 ($1500) compared to the £70 total cost for my gainclone (with case, tranny and ALPS blue velvet).
Well to anybody out there still wondering if gainclones can better a commercial 'hi-fi' amp, I can tell you that it can.
My brother and I both agreed that the gainclone had a much clearer and detailed top end and a more controlled bass. Mids were comparable on both amps. It wasn't night and day but the differences were clearly audible on virtually every test cd we threw at the system.
On another note, Dynaudio 1.3mkII speakers were used for the testing (and arcan CD92 cd player). These are notoriously difficult to drive and amps with 100W pluse per channel are recommended. Well my little gainclone seemed to be able to cope with near party level volumes with out my rather inadequate heatsink get more than warm.
Thinking about a gainclone or chip amp? Do it. They really are that good and I have only heard a basic implementation!
Al
Well to anybody out there still wondering if gainclones can better a commercial 'hi-fi' amp, I can tell you that it can.
My brother and I both agreed that the gainclone had a much clearer and detailed top end and a more controlled bass. Mids were comparable on both amps. It wasn't night and day but the differences were clearly audible on virtually every test cd we threw at the system.
On another note, Dynaudio 1.3mkII speakers were used for the testing (and arcan CD92 cd player). These are notoriously difficult to drive and amps with 100W pluse per channel are recommended. Well my little gainclone seemed to be able to cope with near party level volumes with out my rather inadequate heatsink get more than warm.
Thinking about a gainclone or chip amp? Do it. They really are that good and I have only heard a basic implementation!
Al
It's a nice feeling when you get your first LM3875 going and compare it to some commercial hifi products.
I'll also say that good chipamp implementations will trounce amps costing far more than Arcam's A85.
I'll also say that good chipamp implementations will trounce amps costing far more than Arcam's A85.
The price comparison isn't quite fair, is it ?
The Arcam is a complete integrated amplifier, has a remote control, and does 85 watts continuous.
Arcam's P75 has a power rating of 50 watts, which is more in line with a GC. The P75 sold for $700, that translates to less than £400 msrp in the U.K., and before it was discontinued it could be had for under £275.- For that amount of cash you got a complete product, with warranty, a manual and a plug for a headset.
70 to 275 is about 1:4, constructing an amplifier yourself for 1/4th of the retail value isn't that shattering.
The Arcam uses Sanken SAP darlingtons in the output, i can't imagine the power amp circuit of the A85 to be a marvel in engineering.
I do agree that it is hard for consumer grade amplifiers to compete with GC's.
The Arcam is a complete integrated amplifier, has a remote control, and does 85 watts continuous.
Arcam's P75 has a power rating of 50 watts, which is more in line with a GC. The P75 sold for $700, that translates to less than £400 msrp in the U.K., and before it was discontinued it could be had for under £275.- For that amount of cash you got a complete product, with warranty, a manual and a plug for a headset.
70 to 275 is about 1:4, constructing an amplifier yourself for 1/4th of the retail value isn't that shattering.
The Arcam uses Sanken SAP darlingtons in the output, i can't imagine the power amp circuit of the A85 to be a marvel in engineering.
I do agree that it is hard for consumer grade amplifiers to compete with GC's.
I agree and disagree.
While my GC has no remote it does have a passive pre so it is an intergrated rather than power amp. It doesn't look as nice as the Arcam though unless you go for that DIY je ne sais qua.
Yep I agree with warrently etc but in the case of a GC, it isn't going to be difficult to fix is it. A chip, a couple of resistors and caps.
I was concerned initally about the relatively low power output of GCs as my DIY scanspeak speakers have pretty low sensitivity. But having tried my amp in various systems (including Dyns with ~86 dB/W/M) it seems to deliver enough volume with no problems.
The A85 headphone section is awful. £5 cmoy is considerably better.
1/4 of the cost IF it sounded AS good. It doesn't. It is better. I have no idea what I would have to spend to get a commercial amp that sound as good as my GC.
I'm not trying to be awkward but when I was trying to decide whether to build an DIY amp or just stay with commerical offerings I would have really appreciated some info on peoples experiences of GCs compared to any commercial amps that I could demo.
Al
While my GC has no remote it does have a passive pre so it is an intergrated rather than power amp. It doesn't look as nice as the Arcam though unless you go for that DIY je ne sais qua.
Yep I agree with warrently etc but in the case of a GC, it isn't going to be difficult to fix is it. A chip, a couple of resistors and caps.
I was concerned initally about the relatively low power output of GCs as my DIY scanspeak speakers have pretty low sensitivity. But having tried my amp in various systems (including Dyns with ~86 dB/W/M) it seems to deliver enough volume with no problems.
The A85 headphone section is awful. £5 cmoy is considerably better.
1/4 of the cost IF it sounded AS good. It doesn't. It is better. I have no idea what I would have to spend to get a commercial amp that sound as good as my GC.
I'm not trying to be awkward but when I was trying to decide whether to build an DIY amp or just stay with commerical offerings I would have really appreciated some info on peoples experiences of GCs compared to any commercial amps that I could demo.
Al
An interesting thread. I think it's good to encourage other people who might be thinking about trying a gainclone, and it's certainly true to say that it will sound better than you might think. Certainly, for £70 (plus your time), it's a bargain. My first gainclones cost me much less because I already had the parts, but in my most recent chip-based amp, I paid around £70 just for the mains transformer!
Just as an aside, and not wishing to offend anyone, you forgot to say "in my opinion". I feel that it's important to pay attention to how we express ourselves when talking about subjective matters. Additionally, your "clearer and detailed top end" might be someone else's "forward, aggressive, tiring treble" if this person has speakers or a CD player that is brighter than normal. For what it's worth, I have both a CD72 and a CD92 - the CD92 is much brighter than the CD72, which has a "fuller" (read: less accurate) bass. The CD92 sounds detailed and alive with my ATC SCM20SL's, but when using my Rogers LS3/5a's (which are famed for their bright top end), the CD92 is too bright and also sounds bass-light compared with the CD72. Horses for courses 😉
Some facts about the A85:
The output stage is basically the Alexander CFB amp (look up AN-211 on the AD website). It's a fascinating paper and topology, although I haven't experimented with it or listened to it in any form. The A85 differers from the paper by using Sanken SAP15N/P output devices rather than IGBT's. The op-amp used is the TL071.
There is no "headphone stage" as such - it's the usual arrangement of a resistor in series with the output of the power amp (330ohms, with 100ohms in parallel to reduce the output impedance). This might well account for some of the difference you hear - as an experiment try adding a 75ohm resistor in series with the output of the CMOY. Certainly, when I built a discrete class A headphone amp some 15 years ago, the value of the output resistor affected the sound more than anything else.
The preamp of the A85 is rather complex, and this might well account for some of the differences you've observed. For this reason, why not try bypassing it? Feed your volume control into the "power-amp in" socket...
The signal path consists of DG408 analogue switches in virtual earth mode, in conjunction with an OPA2134 (one half as the amp, the other is a DC servo). Next, the signal is passed to another analogue switch IC (a DG413) which switches in the tone controls if selected. Then, the WM8816 volume control IC, working in conjunction with another OPA2134. Switching in the tone controls introduces a lot more complexity (some TL072's, DS1844 digi-pots, electrolytic capacitors, etc), but of course you're hopefully not using these 😉
Personally, I think the A85 is a solidly engineered piece of work, which offers immense flexibility and a nice user-experience. As a set of engineering compromises, it's a successful product. Subjectively, some of the hi-fi press have said that it doesn't offer absolutely the best sound quality at the price point, but it offers other things instead. For example, potential multi-room or multi-channel operation, full remote control, separate record-out selection, tone controls, AV processor loop operation, remote speakers. Now you might not want any of these features in an amplifier, and the absolute sound quality might be your priority - that's fine. But a company has to decide where to "pitch" its products in order to shift the quantities necessary to make a profit after R&D and production costs, and clearly Arcam felt that more people will expect the mix they offered. And they seemed to have judged their market well if the sales are any indication.
The joy of DIY Hi-Fi is avoiding all the pressure from Marketing people, and being able to leave out the stuff you don't need. Sounds like you're enjoying it 😉
Just as an aside, and not wishing to offend anyone, you forgot to say "in my opinion". I feel that it's important to pay attention to how we express ourselves when talking about subjective matters. Additionally, your "clearer and detailed top end" might be someone else's "forward, aggressive, tiring treble" if this person has speakers or a CD player that is brighter than normal. For what it's worth, I have both a CD72 and a CD92 - the CD92 is much brighter than the CD72, which has a "fuller" (read: less accurate) bass. The CD92 sounds detailed and alive with my ATC SCM20SL's, but when using my Rogers LS3/5a's (which are famed for their bright top end), the CD92 is too bright and also sounds bass-light compared with the CD72. Horses for courses 😉
Some facts about the A85:
The output stage is basically the Alexander CFB amp (look up AN-211 on the AD website). It's a fascinating paper and topology, although I haven't experimented with it or listened to it in any form. The A85 differers from the paper by using Sanken SAP15N/P output devices rather than IGBT's. The op-amp used is the TL071.
There is no "headphone stage" as such - it's the usual arrangement of a resistor in series with the output of the power amp (330ohms, with 100ohms in parallel to reduce the output impedance). This might well account for some of the difference you hear - as an experiment try adding a 75ohm resistor in series with the output of the CMOY. Certainly, when I built a discrete class A headphone amp some 15 years ago, the value of the output resistor affected the sound more than anything else.
The preamp of the A85 is rather complex, and this might well account for some of the differences you've observed. For this reason, why not try bypassing it? Feed your volume control into the "power-amp in" socket...
The signal path consists of DG408 analogue switches in virtual earth mode, in conjunction with an OPA2134 (one half as the amp, the other is a DC servo). Next, the signal is passed to another analogue switch IC (a DG413) which switches in the tone controls if selected. Then, the WM8816 volume control IC, working in conjunction with another OPA2134. Switching in the tone controls introduces a lot more complexity (some TL072's, DS1844 digi-pots, electrolytic capacitors, etc), but of course you're hopefully not using these 😉
Personally, I think the A85 is a solidly engineered piece of work, which offers immense flexibility and a nice user-experience. As a set of engineering compromises, it's a successful product. Subjectively, some of the hi-fi press have said that it doesn't offer absolutely the best sound quality at the price point, but it offers other things instead. For example, potential multi-room or multi-channel operation, full remote control, separate record-out selection, tone controls, AV processor loop operation, remote speakers. Now you might not want any of these features in an amplifier, and the absolute sound quality might be your priority - that's fine. But a company has to decide where to "pitch" its products in order to shift the quantities necessary to make a profit after R&D and production costs, and clearly Arcam felt that more people will expect the mix they offered. And they seemed to have judged their market well if the sales are any indication.
The joy of DIY Hi-Fi is avoiding all the pressure from Marketing people, and being able to leave out the stuff you don't need. Sounds like you're enjoying it 😉
Great post.
Of course all my posts describing 'improvements in sound' represent my opinion, and may well be a result of system synergy, personal preference etc, etc.
My point is simply that IMHO GCs can deliver quality. Whether that quality or presentation matches your prefernces...I can't comment.
P.S. My brother also preferred the GC sound but NOT the lack of other features and a pretty shoddy hammond case. He is staying with the Arcam but is now itching to upgrade. His wife isn't happy with me.
Of course all my posts describing 'improvements in sound' represent my opinion, and may well be a result of system synergy, personal preference etc, etc.
My point is simply that IMHO GCs can deliver quality. Whether that quality or presentation matches your prefernces...I can't comment.
P.S. My brother also preferred the GC sound but NOT the lack of other features and a pretty shoddy hammond case. He is staying with the Arcam but is now itching to upgrade. His wife isn't happy with me.
Agreed.. the comparison is not entirely the Amps..
BUT the Pre sections.
The Arcam Pre is errr... Lame.. at best. The amp section while not the most elegant available sounds substantially better.. Without.. the Poor quality pre amp engaged.
A surprising difference actually ,.
IMO.. every arcam should have it's Pre disabled for a v worthwhile upgrade.
Possibly the Chip Amp is better but at least compare Amp to Amp.
Surprising to hear of a recent Gainclone, I had thouight these were faded dreams.
BUT the Pre sections.
The Arcam Pre is errr... Lame.. at best. The amp section while not the most elegant available sounds substantially better.. Without.. the Poor quality pre amp engaged.
A surprising difference actually ,.
IMO.. every arcam should have it's Pre disabled for a v worthwhile upgrade.
Possibly the Chip Amp is better but at least compare Amp to Amp.
Surprising to hear of a recent Gainclone, I had thouight these were faded dreams.
waltona said:
LOL - I was trying to avoid the "S word"! But it's definitely true...
If you've looked around my site, you'll see that I agree with you fundamentally - basically these LM chips have no right to sound as good as they do! And it's been great over the last 2-3 years to watch so many people dipping their toes into the murky waters of DIY audio, with such good results. Spool back more 20 years ago when was starting with amps, I tried using the TDA2002 (IIRC). These were ok for background music, but even relatively simple discrete designs were subjectively and technically better. Then in 2003 I tried the LM3875s, which were a complete revelation to me.
Well, try an experiment to determine what has most influence on the sound quality. If the preamp sounds ok, then he can just use a gainclone as a power amp, thus retaining all the facilities of the A85. The gainclone can be hidden somewhere, so looks won't be an issue. You could take it further - have monoblocks located at the speakers to reduce speaker cable losses. Maybe even build 4 monoblocks and bi-amp!
However, if the preamp is the culprit, he's stuck. But as I say, try the experiment - I'm in no position to predict the outcome...
Cheers,
Mark
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