Audiophile DIY amplifier kits?

[Martyn]

I'd like to build my own two-channel amplifiers on the assumption that it is possible to achieve very high SQ at a reasonable price (just like speakers).

Can anyone recommend any kits based on personal experience and comparisons with other amps (both DIY and commercial)? I'm competent enough to follow clear instructions, but that's about all. So a kit would have to be reasonably fool-proof as well as having high-end performance. Thanks,

Martyn

[podboy]

How much power are you looking for? If you only need a little (2x25), I would suggest that you checkout http://www.41hz.com/ and the amp6.

[Martyn]

I presently use a 45W/8ohm SS integrated amp. This seems quite adequate although I wouldn't want to go any smaller.

[darwin]

Martyn, You might want to check into the UCD Class D amps. They're available in 180, 400, and 700W versions (at 4 Ohm) - UcD180 AD, UcD400 AD, and UcD 700 AD. The amps, power supplies, etc. are modular and virtually plug and play. They're also relatively inexpensive, but there's nothing low end about their sound, IME. I have two of them driving my Maggies - a two and a three channel UcD400 AD amp and couldn't be happier with their performance.
There is quite a bit of info on them in the Class D section of the DIY Audio forum, and there will be complete kits available soon from DIY Cable (they currently sell everything needed except for the chassis - it should be available soon), which is where I bought mine.

[Martyn]

Thanks, Darwin. I've read a little about these amps. They certainly seem to give good performance at a very reasonable price, but I wonder just how good. My aim is to do this just once to a very high standard, rather than build a series of amps over the years. Thus I don't mind paying more for something that is very high SQ. I'll certainly check out the DIY Audio forum - thanks for your help.

[darwin]

Unfortunately I live out in the middle of an audio no man's land and I've only been able to compare my UcD400ADs to Outlaw Audio M200 monoblocks and an Adcom GFA-555. It's purely subjective, but I much prefer the UcDs to both.
Here's an evaluation of the UcD amps that you might find helpful:

http://www.hardwareanalysis.com/content/reviews/article/1822/

[Martyn]

That's an interesting web site. I notice that Hypex is an advertiser on the site, so I'll be wary of glowing reviews. On the other hand, the reviewer pretty well trashes an amplifier from another advertiser, which is a rare thing these days. At the price, I guess there's not much to lose by trying a couple anyway. Thanks for your follow-up.

[Spearmint]

Another amp that gets good reports is Aska.

http://www.aksaonline.com/

[Martyn]

Yes, these seem to have a strong following, but it's not easy to find out how good they are with any degree of objectivity - and they are too expensive to take a chance on. I'm hoping someone will respond who has done a direct comparison with one or two commercial amps (or with a Hypex UcD!).

[Spearmint]

Yes, these seem to have a strong following, but it's not easy to find out how good they are with any degree of objectivity - and they are too expensive to take a chance on. I'm hoping someone will respond who has done a direct comparison with one or two commercial amps (or with a Hypex UcD!).

I have only heard the Aska amps once when Hugh bought them along to a GTG we had a couple of years ago. We were also fortunate to have Hugh at another GTG last week when we were comparing 2ch pre amps, and Hugh bought his Swift along, one very impressive unit. It won my heart and a couple of others in attendance as well.

As for comparing Hugh’s amps with the likes of Hypex I afraid I cannot help, although I am using Hypex plate amps with my HT subs, and they are a great amp.

[darwin]

That's an interesting web site. I notice that Hypex is an advertiser on the site, so I'll be wary of glowing reviews. On the other hand, the reviewer pretty well trashes an amplifier from another advertiser, which is a rare thing these days. At the price, I guess there's not much to lose by trying a couple anyway. Thanks for your follow-up.

I don't think that either manufacturer advertises on the site. AFAIK, Hardware Analysis is a completely independent reviewer. The owner of the site is also a frequent poster on the Class D forum at the DIY Audio site.
Good luck with your search. I know what a difficult task it can be. I spent almost a year looking at all the different DIY options that were capable of driving my Maggies, ICE Power, LC Audio, and a host of others before finally settling on the UcDs. I almost gave up in frustration and considered more mainstream retail offerings, but I'm glad that I stuck it out.

[PaulHilgeman]

The Hypex modules are great. I have compared them to various Hi-Fi amplifiers and think that the Hypex amps sound great. The UcD180 is a tad short on power, but the 400 is perfect. Take note that my listening room is very large and very damped, so for smaller rooms the 180 should be more than enough.

They have very good sound quality, IMO, better than any of the bryston amplifiers. What else are you thinking of?

Many Class A/B amplifiers seem to loose steam when driven hard, not to clipping or anything like that, but the Hypex modules never seem to be feeling any pain at all, right up until they clip. The SQ is the same wether it be at a low volume or a high volume.

One other great thing that I have noticed, is that they SQ changes very little once the amplifier is on, there are many class A/B amplifiers that for the first 10 or 20 minutes after turning on a cold amplifier, the sound can change quite a bit.

-Paul

[Martyn]

Interestingly, it's the Hypex UcD180AD and the AKSA 100N+ that have been the leading contenders for some time, and both have been recommended in this thread.

I think I may have found one, and possibly two, people in my area who have built the AKSAs, so I'm hoping to be able to arrange a visit.

My "listening room" is the family living room. It's a good size, but the house is also quite open plan. Nevertheless, my existing 45W/8ohm integrated amp can play louder than I'll ever want to listen to (got enough hearing loss already), so I'm assuming that the 180 would suffice. Interesting that you rate them above Brystons for SQ - that's a useful benchmark.

Thanks for your comments,

Martyn

[jonathanb3478]

Nevertheless, my existing 45W/8ohm integrated amp can play louder than I'll ever want to listen to (got enough hearing loss already), so I'm assuming that the 180 would suffice. Interesting that you rate them above Brystons for SQ - that's a useful benchmark.

I too would like to make an amp with the Hypex UCD-180AD modules. I wanted to use the Exodus M-ch power supply sold by DIYCables.com, but I saw it on their website one day, and the next it was gone. That is too bad, as I wanted to build a 2-ch, then upgrade it to a 5-ch over time.

I do not know, however. That setup would end up being over $1200. Not bad when you think about it, but still a lot of scratch.

[darwin]

I too would like to make an amp with the Hypex UCD-180AD modules. I wanted to use the Exodus M-ch power supply sold by DIYCables.com, but I saw it on their website one day, and the next it was gone. That is too bad, as I wanted to build a 2-ch, then upgrade it to a 5-ch over time.

The MCH power supply should be available again at DIYC shortly. They haven't been discontinued. DIYC was having some problems with the supplier, I think. I'm waiting to buy one for a four-channel I'm building.

[Martyn]

One possibility that had already occurred to me is to build AKSAs for two -channel and build a multi-channel UcD for HT. I haven't costed the latter yet, but I suspect that it might be too expensive.

[jonathanb3478]

One possibility that had already occurred to me is to build AKSAs for two -channel and build a multi-channel UcD for HT. I haven't costed the latter yet, but I suspect that it might be too expensive.

Well, I did so maybe it will help. My BOM is not finalized, however. Also, the m-ch upgrade cost assumes I can replace the transformer in the stereo version with a large enough replacement for $100. The total of ~$1275 includes both the original and replacement transformers.

Stereo Class-D 100 watt amp project BOM (In Progress)

Electronic

https://www.diycable.com

Item qty
Exodus MCH Power Supply 1
UCD-180AD module 2
Panisonic 10,000 uf cap 4
S/H $10.78 (UPS) $6.80 (USPS)
Total $487.66

Electrical

https://www.partsexpress.com

Item qty
AVEL 500VA 30+30 TOROIDAL Tx 60.00
S/H $10.00
Total $70.00

https://www.digikey.com

EG1529-ND 1 $1.82 120VAC 15amp black)
501PB-ND 1 $0.94 SWITCH PushButton SPST ON-OFF BLACK
Q210-ND 1 $0.64 AC Receptacle
67-1120-ND 10 $1.50 Red LED (min qty=10)
67-1119-ND 10 $1.65 Green LED (min qty=10)
S/H $11.50
Total $18.05

Connectivity

https://www.redco.com

Item qty
Neutrik NC3FP-1 2 $2.31
S/H $8.00
Total $12.62

https://www.madisound.com

G-POST binding posts 4 $1.25

Enclosure

https://www.lansing-enclosures.com

P2F16-VT3A $99.80(includes 1st time 15% off)
S/H $15.00
Total $114.80

Stereo Amp Only Total $708.13

5-ch Upgrade Total $567.43

Total for 5-ch version $1,275.56

[Martyn]

Do you have anything specific in mind for a 5.1 processor?

[jonathanb3478]

In my case, my DVD player is a 5.1 processor, and I have an analog multichannel preamp in the system I would add the UCD amp to.

Eventually, I would like to setup 7.1 in the bedroom multichannel system. Too far off to start contemplating exact models for the upgrade, however.

[Martyn]

I heard an AKSA 100N+ last night side-by-side with my Linn integrated amp. The AKSA was noticeably faster, cleaner, crisper (those sorts of words). The overall SQ was very pleasing. Although this was by no means a definitive audition, I think it was sufficient to point me towards building a pair of them this coming winter.

[jonathanb3478]

I think it was sufficient to point me towards building a pair of them this coming winter.

Let us know how it goes!

[tamosius]

How about Aussie Amplifiers: http://www.aussieamplifiers.com/index3.htm ?
Any body has experience with them? I'm kind of keen to build a stereo amp... AV800 maybe.. for my future Eton 11.2..

[Martyn]

I eventually decided to go with the AKSA 100N+ after finding an owner in my neck of the woods who brought his to my house for an audition. I too am using Eton 11.2 3-way speakers which I like very much. The faster bass when compared to my Linn Intek (using my Linn's pre-outs) was enough to convince me.

The AKSA kit arrived last weekend. I'm not in any rush and will aim to have it built by Christmas. One of my Etons is presently the subject of an optimisation experiment by a speaker buddy. By early December we should be ready to do a side-by-side comparison of that with the original; I'll make the results available to anyone who is interested, so you might want to postpone your decision until then. Feel free to send me a PM if you want further details.