Hello - I am new to the forum and weeks of agonizing over which amp to build for my system has led me here.
I recently moved to a condo so I won't be able to blast the music like I would have been in the past - however, i'm taking this opportunity to focus on better sound quality. I figure 10-40 watts will be enough.
I looked at one of the popular Pass DIY's but I don't want to chase down unobtanium transistors...
Are there any well regarded, low power Class A or Class AB kits, boards, schematics, that use parts I can buy off DigiKey?
I have an AliExpress LM3886 board coming, which I suspect will I will toss in the bin.
Extra info:
I currently have a pair of JBL 4307s which are rated at 6 ohms and 91db sensitivity. They're being powered off a Sony TA-70 which goes plenty loud for my needs but I find that the bass isn't very tight which I'm guessing is a lack of damping factor with the integrated amp. To me bass tightness is important as I listen to a lot of house music and indie pop.
I have an enclosure for a Pioneer TX-500 tuner which I am going to hollow out and stuff an amp into and add VU meters. I have another Sony TA-70 which I'm converting into a preamp using a simplified (unnecessary parts depopulated) output board from a Pioneer DJM-500 mixer, and taking the power supply outboard.
Some odd choices here I know, but the goal is to have a nice looking, good sounding stereo that fits in an IKEA Kallax shelf
I recently moved to a condo so I won't be able to blast the music like I would have been in the past - however, i'm taking this opportunity to focus on better sound quality. I figure 10-40 watts will be enough.
I looked at one of the popular Pass DIY's but I don't want to chase down unobtanium transistors...
Are there any well regarded, low power Class A or Class AB kits, boards, schematics, that use parts I can buy off DigiKey?
I have an AliExpress LM3886 board coming, which I suspect will I will toss in the bin.
Extra info:
I currently have a pair of JBL 4307s which are rated at 6 ohms and 91db sensitivity. They're being powered off a Sony TA-70 which goes plenty loud for my needs but I find that the bass isn't very tight which I'm guessing is a lack of damping factor with the integrated amp. To me bass tightness is important as I listen to a lot of house music and indie pop.
I have an enclosure for a Pioneer TX-500 tuner which I am going to hollow out and stuff an amp into and add VU meters. I have another Sony TA-70 which I'm converting into a preamp using a simplified (unnecessary parts depopulated) output board from a Pioneer DJM-500 mixer, and taking the power supply outboard.
Some odd choices here I know, but the goal is to have a nice looking, good sounding stereo that fits in an IKEA Kallax shelf
The problem is, components go end-of-life all the time. Especially transistors in thru-hole packages. Available today, gone tomorrow. If you're using a circuit design more than 6 months old, there's a good chance that the designer specified at least one transistor which was available then but not available today.
So the safest course is to start with the available parts, and create a design that uses them exclusively. Buy the parts, 100 pieces of each, and keep your own personal hoard/stash. Now you can build multiple copies of your amp, today, next year, and ten years from today. You've got the parts.
Use one of the Blameless amplifier circuits found in Douglas Self's book "Designing Audio Power Amplifiers", adapt it to the parts you have chosen, and start your build. Success!
So the safest course is to start with the available parts, and create a design that uses them exclusively. Buy the parts, 100 pieces of each, and keep your own personal hoard/stash. Now you can build multiple copies of your amp, today, next year, and ten years from today. You've got the parts.
Use one of the Blameless amplifier circuits found in Douglas Self's book "Designing Audio Power Amplifiers", adapt it to the parts you have chosen, and start your build. Success!
TDA7297, TPA3116, LM1875....
Been around a long time. Still available.
Or go Mosfet, many available in variety, and quantity.
Been around a long time. Still available.
Or go Mosfet, many available in variety, and quantity.
1) It is over 40 years old. I'm not a re-cap guy, but this one is due, especially with that complaint.
2) C705 C706 C805 C806 are half the values I would have used in a cheap amp in 1972. Especially with no NFB around the output caps. Today I would go 470uFd and 4,700uFd. Or as near as will fit (and caps are much smaller now). C303 double or triple.
Sony TA-70 Stereo Integrated Amplifier Manual | HiFi Engine
Smaller amplifiers where the voltages (and currents) are sane are far more forgiving of parts substitutions. In that power range, you can usually find a current production part, that will work, in any given design.
I built a "50 w" apex ax6 with MPS8099 input, D44r2 (GE) VAS, MJE15028/29 as drivers, MJ15003 as outputs. I got 70 W out of it on 8 ohm speaker for 5 seconds at a time. 2n5550/5551 would also work as input (but were more expensive), also MPSA06. MJE15028 should work fine as the VAS. More common MJ21194 could work as OT, or if you only want to drill one hole, MJL3281 or MJL4381 or MJW 3281 or MJW4281 or MJL21194, whatever is in stock at your distributor. If you want the wattage, use heat sinks on drivers, and VAS.
Retro Amp 50W Single Supply diyaudio/ax6 for pictures of my PTP board in a 3.5" high chassis. Apex posts 4.5"x4.5" artworks.
These transistor numbers are common for North American residents. Europeans/Aussies have entirely different part numbers in stock.
If you want more power with dual output transistors, I've found PV-4c, M-2600 and cs400 cs600 sold for parts or repair on ebay or craigslist(gumtree UK) to be economic. I don't use original transistor numbers there either. MJ21194 instead of MJ15024 (outputs) MJE15032/33 for drivers, MPS8098/99 or MPSA06/56 for TO92 transistors. Work fine. Matching dual output transistors for gain or Vbe is important, buy 6 or 7 if you need 4.
BTW the apex 6 equipped ST120 at 1 to 70 watts sounds exactly like the CS800s which is specified at .02%HD into 8 ohms. With XLR input the cs800s has no capacitors in the music flow. The AX6 has one in, one out. This is using my SP2-XT speakers. I now have SP2(2004) speakers which come specified for HD 20 db down from 5 w output, 2nd & 3rd harmonics.
The GE D44R2 TO220 transistors from 70's US production are still for eale at electronicsurplus.com $2.90 for 10, in Ohio. 20 mhz Ft. Way better high freq sound than the TIP31c/32c I used originally as drivers. The ST120 had RCA 50 mhz ft transistors as drivers in 1966. I have a surviving St120 board with the RCA 1966 transsistors that put the AX6 with TIP31c/32c to shame on top octave piano & tinkly bells.
Retro Amp 50W Single Supply diyaudio/ax6 for pictures of my PTP board in a 3.5" high chassis. Apex posts 4.5"x4.5" artworks.
These transistor numbers are common for North American residents. Europeans/Aussies have entirely different part numbers in stock.
If you want more power with dual output transistors, I've found PV-4c, M-2600 and cs400 cs600 sold for parts or repair on ebay or craigslist(gumtree UK) to be economic. I don't use original transistor numbers there either. MJ21194 instead of MJ15024 (outputs) MJE15032/33 for drivers, MPS8098/99 or MPSA06/56 for TO92 transistors. Work fine. Matching dual output transistors for gain or Vbe is important, buy 6 or 7 if you need 4.
BTW the apex 6 equipped ST120 at 1 to 70 watts sounds exactly like the CS800s which is specified at .02%HD into 8 ohms. With XLR input the cs800s has no capacitors in the music flow. The AX6 has one in, one out. This is using my SP2-XT speakers. I now have SP2(2004) speakers which come specified for HD 20 db down from 5 w output, 2nd & 3rd harmonics.
The GE D44R2 TO220 transistors from 70's US production are still for eale at electronicsurplus.com $2.90 for 10, in Ohio. 20 mhz Ft. Way better high freq sound than the TIP31c/32c I used originally as drivers. The ST120 had RCA 50 mhz ft transistors as drivers in 1966. I have a surviving St120 board with the RCA 1966 transsistors that put the AX6 with TIP31c/32c to shame on top octave piano & tinkly bells.
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The ACA kit from Nelson Pass (for sale in the webshop on this site) is a good contender. Buy two (all parts are included) and use them as monoblocks with 15w class A power. That should be enough for your speakers. It's a high rated amplifier, also outside diyaudio, but it's typical coloured for a class A transistor amp. I got one and a second is in the making and these are a steel for what they go for. Assembled on the commercial market these would cost a few thousands i think.
Amp Camp Amp – diyAudio Store
For neutral amps, Icepower seems to be very popular and quiet good. They also sell low power modules.
Amp Camp Amp – diyAudio Store
For neutral amps, Icepower seems to be very popular and quiet good. They also sell low power modules.
For good bass with electronic music
a sub would help
not blasting booming bass either.
just a powered sub
you can also slightly high pass the main speakers
and this will clean up and tighten the bass
since they wont need to work so hard.
far as the amplifier
for 10 to 40 watts
most just stick with chip amps
a sub would help
not blasting booming bass either.
just a powered sub
you can also slightly high pass the main speakers
and this will clean up and tighten the bass
since they wont need to work so hard.
far as the amplifier
for 10 to 40 watts
most just stick with chip amps
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Hello, you can try Pass AB100 - the PCB layout is available (original PASS or PRASI designs). Generic transistors - ztx, bc, TIP outputs - below 40V rails BD139/140 as VAS. You can use + -30V power supply if you do not need 100W. This one has good bass.
AB100 Class AB Power Amplifier
AB100 Class AB Power Amplifier
There’s at least 100 in the Apex thread. But for simple, no unobtanium parts, the Apex FH9 is a great choice. Easy to build and sounds great.
A Directory of Apex Audio Amplifiers
You can build one with common easy to find cast iron griddle as the heatsink. No specialized chassis even needed.
The Cast Iron Griddle Amp - a Budget Conscious Heatsink Solution
A Directory of Apex Audio Amplifiers
You can build one with common easy to find cast iron griddle as the heatsink. No specialized chassis even needed.
The Cast Iron Griddle Amp - a Budget Conscious Heatsink Solution
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Still scratching my head over this one; what´s your REAL problem with this?
You haven´t even SEEN it.
I suspect you listen with your eyes, in which case I would be very hesitant to recommend anything to you.
Just keep reading random Forums and build the one with the most "OOH!!"s and "AAH!!"s accompanying it.
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I suspect that it’s an unpopulated board, and with no 3886’s available it won’t do much good. Might sit for years before anything can be done with it.
My real problem is that I don't entirely trust it... I bought this kit unpopulated but with parts (including the LM3886) included so it gives me the chance to weed out any suspect parts. It's coming from AliExpress so i've set realistic/pessimistic expectations.
I fully expect this to be a learning experience since I'm not even 100% sure what class of amp or topology is best suited for my needs.
I do prefer a more neutral sound so I might splurge on the ICE class D module, that another member mentioned, if this LM3886 kit doesn't work out.
LM3886 fully built with heatsink $28. I have bought these before. They work well and are an amazing value. Just add a linear trafo and chassis.
US $20.80 20％ Off | LM3886 DC Servo Audio Amplifier 2.0 Channels 2*68W High Power Amplifiers Baord Stereo OP07 NE5534 Operational Amp
LM3886 DC Servo Audio Amplifier 2.0 Channels 2*68W High Power Amplifiers Baord Stereo OP07 NE5534 Operational Amp|Amplifier| - AliExpress
US $20.80 20％ Off | LM3886 DC Servo Audio Amplifier 2.0 Channels 2*68W High Power Amplifiers Baord Stereo OP07 NE5534 Operational Amp
LM3886 DC Servo Audio Amplifier 2.0 Channels 2*68W High Power Amplifiers Baord Stereo OP07 NE5534 Operational Amp|Amplifier| - AliExpress
I'm gonna build a 1-2W-version of this one for a compression driver. 4w single ended class-a with very common and cheap parts. You need sensitive speakers though or be limited SPL-wise
Class A, 4 Watt, No Feedback, Simple Circuit, Great Sound
Class A, 4 Watt, No Feedback, Simple Circuit, Great Sound
That’s a neat amp. I would like to try it with a MOT instead of a CCS for 8w. 19v laptop brick would be handy.
Best amp I've found for bass tightness isn't classAB, its classD : Transformer input TDA8932 mono amp
Fits within your power requirements too at 20W.
If you want parts that are common, you'll have to get with the times and build something with SMD transistors.