The part physically burned up. Got hot to the point of smoking, then junk. This happened normally shortly after power up. A couple volume changes, then smoke. Luckily it never happened with an amp and speakers connected.
I think it's better to have a post buffer and AC coupled output as well.
@ammel68 if you provide MCU for MUSES then I can make a board for that chip
Sorry milolag612, but that's outside of my knowledge realm.
Perhaps another forum member here can provide what you need.
If so, I hope you can create a board for this awesome volume control IC for a reasonable cost so others can experience the MUSE's transparency over the TI PGA-series.
Thank you for your interest and good luck friend!
I didn't really find these negative aspects of the PGA23xx but what I did find was a audible noise floor that I just couldn't get rid of. Not very loud but always there.
In the end I made my own digital attenuator that works much better than the PGA23xx and has an inaudible noise floor. Some details here in my project:
http://www.diyaudio.com/forums/anal...-6-input-selector-mdac-attenuator-ir-etc.html
People regularly mention the Muses IC too, like here, but I think it's hard to source?
If you don't need remote control, stick with a stepped attnuator or relay based attenuator.
I wouldn't waste my time or money on any PGA23xx design, nor do I understand why anyone else would.
Been there done that. Not only does the sound of those chips blow compared to a inexpensive stepped attenuator from China, then you have to deal with their tendency to "lock up" and shoot the volume to full blast for no apparent reason possible damaging your speakers! Isn't that oh so lovely??
For a remote controlled option, look for a MUSES 72320 design if you want a volume control chip that sounds literally "transparent" and doesn't have all the glitches/problems of the TI PGA23xx series.
Too bad TI doesn't discontinue these chips and replace them with something comparable to the NJR 72320!
I threw my PGA23xx volume control in the trash where it belongs.
The PGA series have excellent specs. I don't get all this audiophile talk about sounding dull and lack of bass. That is easily measurable and those faults do npot appear in the published measurments. My volume controller, all 24 channels, measures transparent within the audible range.
Let me ask are you using the 2311's or 2320 with +/- 5v analog rails. These will lack headroom if not careful. The 2310 are +/-15v analog rails and will take pro levels. Likewise I have never had one mis count or go full level on it's own. Did you check your SPI buss timing on a multitrace scope? Mistiming could cause things like going full scale. The nice thing about SPI is there are no maximumm timing specs. You can drag the pulse spacing way past the minimum spec and it will still work with added reliability. We hardly need microsecond response time for a volume control.
Sounds like a circuit design problem and not the chip.
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Strange that people are getting bad results. I had a fantastic result with my PGA23xx preamp
Ovation SCA-1: A high performance fully balanced line pre-amplifier
Schematic etc are all up if you want to look.
Esoteric pre amplifiers use the PGA chip - got good reviews
Ovation SCA-1: A high performance fully balanced line pre-amplifier
Schematic etc are all up if you want to look.
Esoteric pre amplifiers use the PGA chip - got good reviews
We are not talking about results though, we are talking about opinions
Audio, like wine tasting or art, is extremely subjective. I would say almost entirely subjective. People have invested large sums of money in their own opinions so are unlikely to be swayed by objective measurements.
I think the PGA's measure exceedingly well - certainly below 10ppm on signal levels below 2V out - so enough to drive any power amp.
On the noise, you might get a better result if you buffer the input. They like to be fed from a low source impedance (so less than 100~200 ohms). I used a dual 4562 per channel to do this. Keep in mind also that at full gain (31.5dB) you will get noise. Most line preamps are 12-16 dB to match the 150-250mV legacy output levels from tuners tape decks and phono stages. In my implementation, I simply set the required gain for the respective input in software - so max gain was 16dB (IIRC) and min gain on CD 0dB.
I will return to the PGAXX again some time in the future but in a more compact, better physical implementation than the SCA-1. The mechanical design was way to big.
On the noise, you might get a better result if you buffer the input. They like to be fed from a low source impedance (so less than 100~200 ohms). I used a dual 4562 per channel to do this. Keep in mind also that at full gain (31.5dB) you will get noise. Most line preamps are 12-16 dB to match the 150-250mV legacy output levels from tuners tape decks and phono stages. In my implementation, I simply set the required gain for the respective input in software - so max gain was 16dB (IIRC) and min gain on CD 0dB.
I will return to the PGAXX again some time in the future but in a more compact, better physical implementation than the SCA-1. The mechanical design was way to big.
Bonsai,
I actually used your blog as reference during my design. Your precedent for using the pga in a balanced configuration was why I went down that road in the first place.
TBH, I could hear a slight difference with the pga in line when I was using it in an unbalanced configuration but I was also using a lower quality input buffer or no buffer so I wasn't sure it was the pga itself. It wasn't bad but I could perceive a difference. Running it differentially with the OPA1632 as a pre/post buffer is perfect to my ears. I couldn't be happier.
Sent from my SM-N900V using Tapatalk
My PGA2310 chain is very simple. I have an SSM2141 balanced receiver, through a 22uf nonpolarized electrolytic cap, Panasonic brand, nothing fancy, to the PGA input. I do this just to protect for any residual DC coming in. The PGA output is DC coupled to an SSM2142 balanced driver. The PGA is run unbalanced, two channels per chip. That's the audio path x24 channels. Obviously I am running a +4 balanced systems here. Audio +/-15v power supply is linear using plain old LM317/337. The separate digital +5v supply is linear as well using another LM317 regulator. I use a JK Microsystems 186 based OEM CPU board for control. It's DOS compatible so easy to program.
Like I said above, they are transparent for all practical purposes. Just like a wire with a gain control!
Like I said above, they are transparent for all practical purposes. Just like a wire with a gain control!
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Glad to hear you ended up with a good result! I wont try and deny that circuits (discrete, integrated or whatever) will have some sonic signature. I guess the ultimate test is 'does it sound good to my ears?'.
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