Yes, no problem with that configuration.Does your system work fine with the speaker cables connected to R+ and L+ as shown in the SMSL diagram?
I don't understand this speaker connection from the electrical operation of the TPA3255.
Yes, no problem with that configuration.Does your system work fine with the speaker cables connected to R+ and L+ as shown in the SMSL diagram?
I don't understand this speaker connection from the electrical operation of the TPA3255.
I dont think there is anything wrong or bad with setting the amp at max in this config and just treating it as a power amp, but yes you are correct there will be a penalty from the DAC in dynamic range if your listening at lower volumes but it is unlikely to be audible as your volume is also low. I could improve this config by setting the amp volume lower allowing me to turn the DAC volume higher. The other option would be DAC in fixed volume, Amps Max volume and treat the Streamer as the pre running the volume control its just the SMSL offers a little finer control over the big jumps on the WiiM.Isnt it bad to Set amp to Max and dac to pretty low signal?
1. This would push the amp to max (possible distortion?)
2. Loses alot of DR because you have to lower DAC signal a lot.
I have been involved with many TPA325x series amplifiers so far, and I think that if they work with AIYIMA's connection method, it is not a PBTL connection. Considering such a connection circuit, the output power should be the same as that of a 2ch BTL connection.Yes, no problem with that configuration.
I look forward to hearing more on this subject as well, when I said no problems that was more of a external configuration statement on setting these up rather than internal connection method.I have been involved with many TPA325x series amplifiers so far, and I think that if they work with AIYIMA's connection method, it is not a PBTL connection. Considering such a connection circuit, the output power should be the same as that of a 2ch BTL connection.
Could someone please explain electrically the internal connection circuit of AIYIMA A07 Max?
You DONT daisy chain them in mono mode!Great effort Aiyima! Monoblocks are great to have more power and less crosstalk
My suggestion to make the device more simple to use is to:
ADD
- A variable/fixed volume switch
REPLACE
- The AUX output with a real RCA subwoofer output
My idea is that monoblock amps typically don't have volume control. You use a preamplifier with those (DAC, preamp, etc.)
It would remove my main concerns:
- Potential volume imbalance between left and right channel
- Running the amplifiers at max volume in mono mode
- Having a AUX output to daisy chain two mono amplifiers is weird and confusing.
One of the goals of having mono amps is to seperate the two channels early in the chain to diminish the crosstalk (compared to a stereo amp). Daisy chain two mono amplifiers?! Why?!?
I really hope you're right !You DONT daisy chain them in mono mode!
They each connect directly to pre amp via their Left rca input when in mono mode.
A volume bypass would be very welcome & I'm just surprised that none of these little amps are available without a volume control, even though they are often listed as power amps.
Good to know about that mandatory feature!i'm thnking mandatory vol. ctrl. is a Chinese market thing
with a TRUE power amp then you limit the usuability... you must have a preamp or dac preamp etc.
and for these companies it limits the market - my feeling is the chinese market really does not get along with true power amps
the vast majority of people want to hook the amp up direct to a pc or whatever
Looking at the connection between BTL and PBTL in the TPA3255 data sheet, in PBTL, one channel of the input is connected to ground, and the speaker output channels of L and R are connected in parallel. However, AIYIMA's monaural connection (PBTL) explanatory diagram does not show such a connection configuration. If you connect the speaker between the L/R + terminals as shown in the illustration, there should be no sound.
I have yet to get mine from Aiyima, but I am going to use it strictly for stereo. I remain hopeful that one of these manufacturers will make true monoblocks at some point, amp with no V/C, just input for one channel power, with volume controlled by a matching style preamp that has 3 inputs, a good stepped volume pot, remote control, volume display LED.
Yes I saw that and that's why I thought it summed the two RCA channels when in mono mode. But it looks like just the left channel is used.I really hope you're right !
I think this is what confused me:
https://www.aiyima.com/products/aiyima-a07-max?variant=46847926239508
View attachment 320355
Pretty sure there should be ONE RCA cable (not two).
Now I am wondering why Fosi’s new amplifier have even lower published specs in mono, even lower than A07 Max.I couldn't understand the operation of AIYIMA A07 Max's monaural mode, so I looked into the TPA3255 data sheet in detail. I also found out that the TPA3255 has four operating modes depending on the combination of M1/M2 pins.
Its four operating modes are
1. 4ch SE connection mode
2. 2ch BTL connection mode
3. 1ch BTL connection mode
4. 1ch PBTL connection mode
There are 4 types.
The strange thing about A07 Max's monaural mode
1. Normally, with PBTL connection, the output load is allowed up to 2Ω, but there is no mention of 2Ω load, and the display remains the same as BTL connection.
2. The output power in monaural mode has not increased much from 2ch BTL. Normally, if you use monaural with PBTL connection, you can get twice the output of 2ch BTL.
3. Adoption of a speaker output connection method that is unimaginable with PBTL
Previous monaural Class D amplifiers used PBTL connections, but the A07 Max seems to use BTL monaural mode from the catalog data.
This operation mode completely stops one channel of the BTL 2ch stereo mode and operates as 1ch monaural.
Looking at the spec data of A07 Max, normally in PBTL monaural mode, the output is twice that of BTL stereo mode, but the output in A07 Max's monaural mode has not increased much from 2ch stereo. There is no mention of PBTL 2Ω in the output load. All of these points can be explained by using BTL monaural mode.
This is just my personal opinion. The actual circuit is unknown.
I don’t think that’s unusual when bridging an amp?I ordered two 07 Max and waiting for delivery. Here is part of their web page and description of the amp. Did anybody try to connect that way: Mono Max Output Power(switch mono mode):600W/ 2Ω(48V/12A)
(R+ connect to speaker +, L+ connect to speaker -)
L+ to speaker - (??)
You are probably right, but I continue to hope that Fosi will release some "pure" amps without a volume pot. I'd like to be able to control via one preamp, one volume pot for both channels. If not monoblocks, then something that would be the Class D answer to the Schiit Vidar 2 but coming in the $200-300 range. Much higher than that, and it would be too close to the Hypex 2-channel builds, such as Buckeye, VTV, etc.While I agree that would be great, I have to think the market for genuine mono blocks, with one tap going in and feeding one channel only, appeals to a very small market. Also, the amount of power typically cranked through mono blocks by 'enthusiasts' is much higher than the vast majority of users ever call for, making for a niche market IMO. I think that the sweet spot for these manufacturers is probably something akin to the A07 Max or the upcoming Fosi ZA3, hopefully with load independence.