I'm looking for a relatively simple class AB build that would be a step up from a chipamp. A proven design with ready to go PCB and easily available current transistors would be very nice. I've seen a few designs that looked nice but either didn't have a pcb sold anywhere or more often had transistors that were long obsolete and hard to find. Elliot Sound Products is having serious shipping issues during the pandemic or I'd probably go with one of those designs.
There's a 100 watt per channel amplifier here on diyAudio, called AB100. It was designed by Nelson Pass and sold as a commercial product for a very brief time. Nelson Pass posted the Gerber CAD files he used to make the PCB. Numerous diyAudio members have built the amp using Pass's PCB design, and they appear to be pleased with the result. You could ask them if they have a couple of left over PCBs to sell you, or if not, you could ask them to hold your hand and gently tutor you through the (quite simple!) process of sending Gerber files to a PCB fab, and getting finished boards back.
However it's a pretty long Forum thread with a lot of posts to read. The discussion of the commercially sold amplifier using the AB100 design, for example, is buried in there but certainly not on the first page. Same goes for Mr. Pass's post with Gerber files as an attachment. You might not want to invest the effort to read, or at least skim, all of those messages. {Pro Tip: there's a setting which lets you see fifty messages per screen rather than ten.} In that case you will probably want to investigate other possibilities.
However it's a pretty long Forum thread with a lot of posts to read. The discussion of the commercially sold amplifier using the AB100 design, for example, is buried in there but certainly not on the first page. Same goes for Mr. Pass's post with Gerber files as an attachment. You might not want to invest the effort to read, or at least skim, all of those messages. {Pro Tip: there's a setting which lets you see fifty messages per screen rather than ten.} In that case you will probably want to investigate other possibilities.
How about a honey badger? That's a good sounding amp, plenty of active devices to choose from. PCBs from DIY audio store. A lot of documantation and even a build guide.
I also voted for the AB100 and if you don't need 100W - you can reduce the supply voltage and the number of output transistors. The AB 100 is relatively simple and very good sounding (descent lower end, great dynamics and sound-stage.. and clear top end) DIY amp (believe me - I have some DIY amplifiers for comparison, also a stack of chipamps)
In addition, the author of the this amap is the mighty and all-respected NP 🙄
In addition, the author of the this amap is the mighty and all-respected NP 🙄
Are there easy to get replacements for the 2SC2590 and 2SA1110? The BOM I found lists 2SC1943 and 2SA1837 which also seem to be discontinued.
It depends on what you want to get out of it:
- A better amp, i.e. better distortion specs, then the Honey Badger is the better choice. This would be at the expense of complexity and build difficulty.
- A more complex build experience over a chip amp, but not too bad, then something simpler like the NAP140 or the AB100.
- A better amp, i.e. better distortion specs, then the Honey Badger is the better choice. This would be at the expense of complexity and build difficulty.
- A more complex build experience over a chip amp, but not too bad, then something simpler like the NAP140 or the AB100.
maybe I'm wrong, but I haven't seen the distortion specs for HB .... In addition, some builders have stability problems with their builds. In any case its a nice circuit and designer of it had some more circuits- slewmaster for example, but they can be too complicated for beginner.
Chinese clones NAP140, MX50 etc do not consider?
Doubtful details can be replaced.
There may be a long waiting period or expensive delivery.
Doubtful details can be replaced.
There may be a long waiting period or expensive delivery.
some builders have stability problems no matter wich amp is build. In a honey badger case, it's do to human error or a faulty part. If one follows the build guide (and use transformer voltage that match the load you want the amp to drive) , don't use iffy parts, and solder well, there is no issues. And of course use enough heatsinks.
The most popular thread in all of DIYA is this:
100W Ultimate Fidelity Amplifier
It got too unwieldy to find anything so I created a directory for the amps contained in that thread:
A Directory of Apex Audio Amplifiers
You will find many great sounding easy to build, easy to source parts 100w amps in that thread. If you want to narrow down the choices into something that has been voted great sounding, boards are available, and assembly and build is supported here on DIY, check out this thread:
Apex Audio Recomendation
It's the FH9, can be assembled in a few hours with $15 in parts. Step up to the FH9HVX and BOM is $32 from Mouser. Perfomance will be better at predicted 0.003% THD at 25w into 8ohms. Only a single pair of Fairchild FQA mosfet outputs needed for 100w. The sound is definitely several steps up from a chipamp...
Uses all the typical, easy to find, inexpensive transistors: 2x KSC1845, 2x KSC3503, KSA1381, MPSA92, and a BD139 for the temp feedback sensor. Outputs are FQA40N25 and FQA36P15. 9 transistors, hence the name FH9 accordign to Apex Audio's naming convention.
100W Ultimate Fidelity Amplifier
It got too unwieldy to find anything so I created a directory for the amps contained in that thread:
A Directory of Apex Audio Amplifiers
You will find many great sounding easy to build, easy to source parts 100w amps in that thread. If you want to narrow down the choices into something that has been voted great sounding, boards are available, and assembly and build is supported here on DIY, check out this thread:
Apex Audio Recomendation
It's the FH9, can be assembled in a few hours with $15 in parts. Step up to the FH9HVX and BOM is $32 from Mouser. Perfomance will be better at predicted 0.003% THD at 25w into 8ohms. Only a single pair of Fairchild FQA mosfet outputs needed for 100w. The sound is definitely several steps up from a chipamp...
Uses all the typical, easy to find, inexpensive transistors: 2x KSC1845, 2x KSC3503, KSA1381, MPSA92, and a BD139 for the temp feedback sensor. Outputs are FQA40N25 and FQA36P15. 9 transistors, hence the name FH9 accordign to Apex Audio's naming convention.
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I built four Honey Badgers. Very, very good amp! My chipamps are toys compared to the Honey Badgers.
Yes. it's a very nice amp. I've build a 5ch honey badger. That was kind of complex. I did spend a lot of time calculating the space, wiring, layout and find parts that would fit my space 🙂 But it was a extreamly fun build.
