Hi
I am looking for a small class AB or B Amplifier with around 50-100W with an onboard PSU where I only need to connect the transformer and do not need a separate PSU. The idea is to convert my nice small studio monitors from passive to active. Each Speaker would have his own mono Amp, and the Filtering will (in this case) be passive. I tried with class D modules but I miss a bit the musicality. Class G would also be OK. If the PCB artwork has already be done, even better as I am not the master PCB designer.
Any suggestions would be warmly welcomed.
Best regards
Christoph
I am looking for a small class AB or B Amplifier with around 50-100W with an onboard PSU where I only need to connect the transformer and do not need a separate PSU. The idea is to convert my nice small studio monitors from passive to active. Each Speaker would have his own mono Amp, and the Filtering will (in this case) be passive. I tried with class D modules but I miss a bit the musicality. Class G would also be OK. If the PCB artwork has already be done, even better as I am not the master PCB designer.
Any suggestions would be warmly welcomed.
Best regards
Christoph
Buy mono 2030 / 1875 / 2050 boards or similar, use appropriate supply.
How big are your speakers, and your room?
Surface treatment of room?
Is there space inside the cabinet for mounting?
Is the cabinet made of a material that is reasonably fire resistant?
How will you dissipate the heat from amp?
In India, generic stereo amp boards are sold, with direct low voltage AC supply, the rectifier etc are on the populated board.
See if you get something in mono.
50-100W is too much for most houses, hence my questions.
How big are your speakers, and your room?
Surface treatment of room?
Is there space inside the cabinet for mounting?
Is the cabinet made of a material that is reasonably fire resistant?
How will you dissipate the heat from amp?
In India, generic stereo amp boards are sold, with direct low voltage AC supply, the rectifier etc are on the populated board.
See if you get something in mono.
50-100W is too much for most houses, hence my questions.
Hi. The speakers are small ones, the room varies. The studio is rather small, but sometimes I listen in another room with 50qm... I know that 50W is a lot but I want a margin for the bass. And I like to listen loud 🙂 I tried lower Watt Class D Amps and it did not sound well. But in AB this might be different... What power does the solution you mention have ? By the way I prefer transistors to the tda chip amps...
Small speakers will burn at 50 Watts.
Transistor 40 W/channel amps are sold here, but will blow your speakers.
Find a set of speakers for the 50 sq. meter area, and if you are not experienced at this, buy an old system, they go very cheap these days, out of 'fashion'!
Transistor 40 W/channel amps are sold here, but will blow your speakers.
Find a set of speakers for the 50 sq. meter area, and if you are not experienced at this, buy an old system, they go very cheap these days, out of 'fashion'!
I have enough speakers around and no you’re not right. at the moment the monitors run on a RAM amp which can produce 1000W per channel. Nothing burns here and I know what I do 😎 Thanks anyway
1000W per channel?
In 50 square meters?
How loud does it get in dB?
How many amps are your fuses?
And output devices are?
And your small speakers have not blown up?
Wonderful.
In 50 square meters?
How loud does it get in dB?
How many amps are your fuses?
And output devices are?
And your small speakers have not blown up?
Wonderful.
Those 386 or TDA7293 chip amp modules with PSU onboard might fit the bill perfectly. Like these for example. They work quite well and simple to connect.
For example:
https://a.aliexpress.com/_m0DC2iw
https://a.aliexpress.com/_mM49Vwq
For example:
https://a.aliexpress.com/_m0DC2iw
https://a.aliexpress.com/_mM49Vwq
Thanks XRK. I had a look at it and one of the companies also sells transistor modules. I would still prefer a US or European source/design. Will see…
regards
Christoph
regards
Christoph
I have both of the boards xrk971 mentioned, I like them quite a bit. Another board you might want to look out for that I think is fantastic is this, https://www.aliexpress.com/item/2255801036997832.htm
Going down the route of a bit more power, I also have https://www.aliexpress.com/item/2251832852542243.html but an earlier version that is identical but uses an NEC UPC2581V instead of the Sony CDX9986L
Of the Chinese/Aliexpress amps I have, the LM1875 is by far my favorite, with the GHXAmp board being the runner up. I do like the LM3886's and TDA7293's but there are more warmth to the other two. Bear in mind that I didn't actually use any of the components in the kits, just their boards and sourced my own parts from digikey/mouser/TI, I was unable to find an NEC UPC2581V so I am using the kit part there. I'm also still waiting (forever) for some legit LM3886T's and TDA7293's to one day ship from mouser, so perhaps my thoughts on which amp is superior may change.
Going down the route of a bit more power, I also have https://www.aliexpress.com/item/2251832852542243.html but an earlier version that is identical but uses an NEC UPC2581V instead of the Sony CDX9986L
Of the Chinese/Aliexpress amps I have, the LM1875 is by far my favorite, with the GHXAmp board being the runner up. I do like the LM3886's and TDA7293's but there are more warmth to the other two. Bear in mind that I didn't actually use any of the components in the kits, just their boards and sourced my own parts from digikey/mouser/TI, I was unable to find an NEC UPC2581V so I am using the kit part there. I'm also still waiting (forever) for some legit LM3886T's and TDA7293's to one day ship from mouser, so perhaps my thoughts on which amp is superior may change.
Asking the hard questions 😀 I'm not 100% positive but I would estimate around $100, maybe a bit more per board. I've never tried any of them with the kit parts, so they may very well be great without subbing anything. I probably went down too deep of a rabbit hole with them, but once I realized that certain parts were almost certainly fake, I lost faith in the parts authenticity. An example being the Unisan TDA7293 board linked above comes with Rubycon USR 10000uF 63v 105C capacitors. Rubycon's datasheet says the USR series is 85C only. Maybe all the kit parts test fine and perform great, but I just feel better knowing that my stuff from mouser/digikey/etc is the real deal.
Hi,
since aliexpress is banned* here, if it is not too much trouble can you post images of the amp (Download-upload) as few sellers do have some old stocks here.
offtopic :
some boards similar to these...
claim to have regulated supply (probably for preamp section) any advantage of that ? And what is extra opamp's (2 out of 4) purpose ?
thanks and regards
*images can be seen though but website can not be accessed
Hope the attached images help. There's a pic of the LM1875, it's low-res schematic in case that interests you, and the one that uses the NEC UPC2581V/Sony CDX9986L as well as it's schematic. The Unisan amp you shared matches the pics of the LM3886 boards out there, and there are near identical TDA7293's.
Attachments
Forgot to mention, on the LM3886 and TDA7293 boards, there are input opamps, and the 2 closer to the amp chips are DC servos.
https://www.diyaudio.com/community/...e-compensated-class-b-retro-amp.385080/page-5
or if ou prefer even more simple design, just ask LKA for "DanWatt"
both amps are of excellent sound with a near artistic PCB design (of LKA)
cheers
zs.
or if ou prefer even more simple design, just ask LKA for "DanWatt"
both amps are of excellent sound with a near artistic PCB design (of LKA)
cheers
zs.
Try this one , very good sounding amp
http://www.modelpromo.nl/audio-dand...Speaker/The Liionidas Open Baffle speaker.pdf
http://www.modelpromo.nl/audio-dand...Speaker/The Liionidas Open Baffle speaker.pdf
If you want to know how much power you actually need, play some music and measure the peak voltage on the amp output with a scope.
Use non compressed music that actually has peaks.
On mine Im usually at 1W average and 20V peaks, so a 50W amp would be fine, lower would risk clipping, higher a waste of money and idle power.