advertisement


Class A Amp

neilmack

neilmack

pfm Member
I've been looking at Joe Henry's Pass-like amps on eBay, of which I have heard good reports. Anyone care to recommend one in particular? What other Class A amps are out there? I heard the previous model Sugden A21a which sounded very well to me. Budget - tops -£1200, preferably less, as I like to eat once in a way.
 
Very few do better class A than Colin Wonfor, he has a single ended DIY kit available I believe. He has tell you more: @CJ14
 
I have a pair of DIY 'Pass' Aleph 60 monoblocks and before that had a 30 power amp. Aside from the great sound, it's built well, has very few parts and is incredibly reliable. I can highly recommend the Alephs and the F6.
 
The proac fb group moderator just loves his stuff and always saying how good it is .go for it , sugden sells easier but of course more expensive in the beginning. As for type, that depends on your speakers I think
 
If DIYing I'd be tempted to make a Krell KSA50 but certainly not using any of the myriad built up boards on ebay etc.
Get the unpopulated boards and source all the parts yourself from trusted sources (not ebay!).
 
You can build your own for under £800 using PCBs from DiyAudio / DiyAudioStore, chassis from Modushop, etc. Here is a thread I started after I finished my Pass F5.

I totally understand if you want something already finished though. It's a lot of work, but a lot of fun to push through one of these builds. The funny/sad part is I am considering selling my Pass F5 amp and BA2018 preamp (designed by a Pass employee) and I haven't even finished the preamp. The problem is the amp puts out a lot of heat, kind of like having a toaster on in the room the whole time you are listening to music. Might not be a problem in some places where you heat year round, but in Valencia it tends to mean having another fan on, or worse, A/C.

49878934636_ec2956d95b_c.jpg
 
There is a lovely pass diy on art of sound from a well know forums 750 pounds

"Many of you will recall Dave Hewitt as an active member on AOS. This is a clone he made of the Pass F3, though with some improvements. I thought it appropriate to post it on AOS, in memory of Dave.
It’s 15 watts pure Class A single ended. It also includes a B1 buffer stage on the input for ease of connection choice. Has dual toroids, Aerovox caps. Lovely Italian made case with solid Aluminium front. Chord cable for all power supply wiring plus Silver signal wiring. Typical Class A sound, very like a valve amp but faster with more control (his words). He sat listening to my Ocellia Calliopes playing from this, saying “It’s like sitting in giant headphones”. He loved them.
I’ve used several pre-amps into the F3; LDR; Pass B1; Stereo Coffee, plus my modded Hafler DH 101/112. All good.
Never thought I’d sell this but am bowing to the inevitable; Tinnitus is spoiling listening for me so I’m slimming the hi-fi
It’s a heavy amp, hence the handles! So, ideally, collection from Bristol (J 18, M5)"

https://theartofsound.net/forum/sho...F3-Class-A-single-ended-Power-Amp-Dave-Hewitt
 
Last edited:
If in UK, Sugden would be my first choice. High quality, built to last, very good after sales service and neat design.
I was lately also very impressed by a pure class A integrated from Luxman but price is very, very high !
Another very good one is Accuphase but again rather expensive but keeps its value over time.
 
sq225917 said:
booja, thats proppa, speaker protection, softstart, beautiful work.
Click to expand...
The electronics part was like a coloring book for me. It's someone else's design and I'm just filling it in (fun, but limited understanding). I had way more fun designing and 3D printing brackets, doing layout, etc.

After I finished the amp I decided to build the pre. I designed coordinating fascias in CAD, sent the drawings to Modushop, and they produced them. I'll have real photos soon, but here's a drawing of the pre and amp:

50314485373_08cda48369_z.jpg


If I sell these I am thinking my next project could be to find a non-working Sansui AU-717 (or similar) and restore it. Might be a better way of learning than just sticking components in PCBs. :) Plus, I already love the AU-717's aesthetics so I won't be focusing on that so much instead of learning more about analog electronics.
 
Gervais Cote said:
+1 for the AU717, it’s a lovely amp with warmth and no listener fatigue at all.
Click to expand...
Let me know if you know of a good one for sale. They are have just about doubled in value over the last 10 years! There's a nice AU517 for sale near me but I kind of want the top of the range one (and 20 more watts).
:)
 
Last edited:
Arkless Electronics said:
If DIYing I'd be tempted to make a Krell KSA50 but certainly not using any of the myriad built up boards on ebay etc.
Get the unpopulated boards and source all the parts yourself from trusted sources (not ebay!).
Click to expand...
I don't think I'm up for building my own.
What would be a sensible price to pay for a used KSA50, and what are the issues to look out for?
 
Gervais Cote said:
If in UK, Sugden would be my first choice. High quality, built to last, very good after sales service and neat design.
I was lately also very impressed by a pure class A integrated from Luxman but price is very, very high !
Another very good one is Accuphase but again rather expensive but keeps its value over time.
Click to expand...
Definitely one of my front runners I think, especially because of the support/service available.
 
neilmack said:
I don't think I'm up for building my own.
What would be a sensible price to pay for a used KSA50, and what are the issues to look out for?
Click to expand...

It's probably a bit over your budget.... About £1k would be a decent ish price but as with ANY amp that's now nearly 40 years old it will need a complete rebuild to be at its best. About another £700 - £1100 for rebuild depending on what is needed/how thorough a rebuild.
I struggle to think of anything at any price that really betters a good one even today...
 
booja30 said:
Let me know if you know of a good one for sale. They are have just about doubled in value over the last 10 years! There's a nice AU517 for sale near me but I kind of want the top of the range one (and 20 more watts).
:)
Click to expand...
You may also consider these that are a close match with a more decent price :

Pioneer SA 9800 (the one with two transfos)

Kenwood KA 9100 (again with two transformers)

These are usually cheap.
 
Gervais Cote said:
You may also consider these that are a close match with a more decent price :

Pioneer SA 9800 (the one with two transfos)

Kenwood KA 9100 (again with two transformers)

These are usually cheap.
Click to expand...
The thing is, I find the old Sansuis are more timeless designs. The 517/717 look like they could have been made in the last 10 years. The silver stuff from the 70s looks like the era it came from -- unless it's Yamaha since that stuff still looks the same!
 
neilmack said:
I've been looking at Joe Henry's Pass-like amps on eBay, of which I have heard good reports. Anyone care to recommend one in particular? What other Class A amps are out there? I heard the previous model Sugden A21a which sounded very well to me. Budget - tops -£1200, preferably less, as I like to eat once in a way.
Click to expand...

Here’s a KSA 100 you may be able to afford. I’m tempted myself.

https://www.hifiwigwam.com/forum/topic/136388-krell-ksa100/page/2/
 
You must log in or register to reply here.


advertisement


Back
Top