Thanks for both of your comments Eric. It gets warm and I am keeping an eye on the temperature. I hope the 48v smps arrives soon.
Yes, indeed -- very nice! Congrats!
Please report back (in a while -- enjoy it for now 😉) on how you like that stepped atten volume control -- it looks like a really neat thing.
Please report back (in a while -- enjoy it for now 😉) on how you like that stepped atten volume control -- it looks like a really neat thing.
Thanks for the nice comments everyone. It has over 50 hours of use now. The stepped resistor volume is great except for not having an open circuit at min volume so I can still hear something.
My 48v smps arrived! It took 10 minutes to swap over. It’s still 400w so I am not sure what the output of the amp actually is. My speakers can take it so I think 90-100w at 8ohms. I think the sound is now a tiny bit warmer, is that possible?
I just need some little rubber feet, some interesting wood for the front and possibly a power light. But for now I am just going to enjoy listening to lots of music.
My 48v smps arrived! It took 10 minutes to swap over. It’s still 400w so I am not sure what the output of the amp actually is. My speakers can take it so I think 90-100w at 8ohms. I think the sound is now a tiny bit warmer, is that possible?
I just need some little rubber feet, some interesting wood for the front and possibly a power light. But for now I am just going to enjoy listening to lots of music.
I managed to keep the 24v 400w smps for £33. Then I went on eBay to buy a 10k DACT Type SMD Stepped Attenuator 21 step volume control. It is the one I had originally intended to use. Anyway one thing led to another and I bought a second one too and some speaker terminals, rca plugs, on/off switch and a 3eAUDIO TPA3251. I will look for a nice case and volume knob for this next project.
I might have Rick! I will post what I think of the new stepped attenuator when it gets here. The trouble I have now is my amp is too good, I can hear all the hissing in some of my older music, even remastered hi-res stuff. New music sounds a lot cleaner, so I need to expand what I listen to.
On my next TPA3255 "non public board" project, I will try this Digital Volume board :
It is really interesting because it includes a BVC input that allow you to add a Bluetooth controler later )
It is really interesting because it includes a BVC input that allow you to add a Bluetooth controler later )
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On my next TPA3255 "non public board" project, I will try this Digital Volume board :
It is really interesting because it includes a BVC input that allow you to add a Bluetooth controler later )
Does this company have a Bluetooth board for this controller as I couldn’t see anything listed on their site. They also don’t say what chipset is used ?? They do have an IR based one listed. They do another model that already has the Bluetooth capability on the volume control board.
Given the amount of trouble you have gone to with rolling the Op Amps on the main board I always get worried about front ending your audiofile power amp with a cheap Chinese volume control. TI do a chipset for a volume control that some people seem to think is good enough to put in front of the TPA3255 series amplifiers.
I do not know so much about this volume control. It does not work like a regular potentiometer. It is a kind of digital volume control(chipset based) that needs a 12V DC to 35V DC PSU. But I own it =) You can also mute it when pressing into the center of the volume knob.
As soon as I get my non public TPA3255 Board from Zero Zone, I will give a try )
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Sure, the best I can do since it is really tiny...
If you zoom in, you would be able to check.
I see something like ATMEGA 328P UTH ....by ATMEL
ATmega328 - Wikipedia
Amazon.com: FlashTree 【2 Pcs】 ATMEGA328P-AU QFP ATMEGA328-AU TQFP ATMEGA328P MEGA328-AU SMD New: Home Audio & Theater
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So it uses basically an arduino(328P) to supply the PT2257 chip the SCL and SDA lines. There are github library files to do the same thing. You "could" make your own with a Nano.
Sure, the best I can do since it is really tiny...
If you zoom in, you would be able to check.
I see something like ATMEGA 328P UTH ....by ATMEL
ATmega328 - Wikipedia
Amazon.com: FlashTree 【2 Pcs】 ATMEGA328P-AU QFP ATMEGA328-AU TQFP ATMEGA328P MEGA328-AU SMD New: Home Audio & Theater
So the little chip in the middle is a PT2257 digital volume control which is controlled by the Atmel custom programmed processor. Quite simple but not too sure how transparent the volume control will be. This company does other boards that already has the Bluetooth remote control functionality already built in so you can control it with an App on your mobile phone.
Attachments
Wondom / Sure is making the same with a split board....
I read good opinions about it :
WONDOM AA-AB41116 PT2259 Module controle de volume numerique encodeur rotatif - Audiophonics
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Or this one :
Distorsion = 0.0004% @ 1kHz with the chip : TI PGA2310
Module controle de volume PGA2310 avec Encodeur Rotatif - Audiophonics
Or with PGA2311
WONDOM AA-AB41148 VC05 PGA2311 Module controle de volume numerique - Audiophonics
Distorsion = 0.0004% @ 1kHz with the chip : TI PGA2310
Module controle de volume PGA2310 avec Encodeur Rotatif - Audiophonics
Or with PGA2311
WONDOM AA-AB41148 VC05 PGA2311 Module controle de volume numerique - Audiophonics
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Wondom / Sure is making the same with a split board....
I read good opinions about it :
WONDOM AA-AB41116 PT2259 Module controle de volume numerique encodeur rotatif - Audiophonics
So Dom/Sure kit seems to have pretty good reputation. The TI chip has much better specification with lower distortion. I think the TI chip is used in some quite high end kit but the boards tend to be more expensive. Just do a search on amazon or eBay.
They also do a PGA2311. Not sure the difference or if just a later version.
This chip looks much better spec !!
TI also introduced the PGA2320 which is even better but I don’t see any products based on it yet.
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That's what I use on mine. It's pretty good. Have to have an external 12v buts that's doable. It also has low output impedance.
WONDOM AA-AB41148 VC05 PGA2311 Module controle de volume numerique - Audiophonics
WONDOM AA-AB41148 VC05 PGA2311 Module controle de volume numerique - Audiophonics
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It is really great and performs well ! Only issue = its size....
I first wanted to add it on my new DIY project but too big to fit on this enclosure with my next TPA3255 board :
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