Start a new topic

Digital PWM Input for HiFimeDIY-Amps (e.g. T4)

Digital PWM Input for HiFimeDIY-Amps (e.g. T4)

Hi there,



I was following your site and the Forum for a long time. I just finished a TI TAS3308 based DSP which has besides the i2s-Outputs also 6 digital PWM Outputs, which can be used to drive a PWM-Amp to be completely in the digital domain. TI call this PurePath HD and it was also used in Equibit/TACT and some Panasonic amps.



I read that the T4 has PWM inputs. The TAS3308 will bring out 2 PWM-Lines (+/-) for each channel. Is it possbile to simply connect these lines to the T4 or are there additional things to consider?



Currently the T4 is out of stock. Will it be back again? Do have the other amps like T3S (STA517b) also a possibility to connect PWM Inputs?



Thank you very much and greetings from germany.



PS: It would be highly interesting to see a new HifimeDIY DDX Amp with TI PurePath Technology (e.g. TAS5518 for DSP/PWM and TAS5631b 300W per Channel). The current DDX v2.1 has in my point of view too low power and the lack of DSP Features like Delay or FIR-Filtering. The TAS based PWM-Processors bring a comfortable GDE (Purepath-Studio) with them, where you can edit the DSP-Features. TAS5518 has also 8 Channel PWM out which would be cool for BI-Amping.
Hi, and sorry about slow reply!
We don't know TAS3308, but you can try to connect the pwm out to the T4, it wouldn't break anything.

We will have some T4 ready in 1-2 weeks.
Hi, and sorry about slow reply!

We don't know TAS3308, but you can try to connect the pwm out to the T4, it wouldn't break anything.



We will have some T4 ready in 1-2 weeks.



As my T4 will arrive soon, I was looking at the T4 schematic to see how to connect the PWM lines to the T4. Can you please have a look and verify that I am going to connect it right.



Connector CN5 is for the second PWM Input and connected to a multiplexer. PINs 1, 2, 4 and 5 on CN5 will be connected to the PWM signal. PINs 3 and 6 can be used as Signal-Ground. Is this so far correct?



Do I need to tell the multiplexer to use the PWM signal from CN5 instead of the TC2000 PWM signal? How should this be done? Connecting Pin 8 to 9 (+5V) on CN5 to get mSel on high?



Thanks for clarify!
Well, I tested it. I can hear a short second the Test Tone from my PWM Processor, but then the Relais will go down. Voltage is ok (30 Volts), I also tried a higher voltage supply.



I gave the PWM Signal only to channel 2 and I brigded Pin 8 (Select of Multiplexer) with Pin 9 (5 Volt) on CN5 in order to select the second PWM-Input. I will try it again with both channels on, may be thats the problem why the relais will go off. The PWM Signal from TAS3308 seems to be ok itself, as I can hear the 1 khz Testtone.



Thank you for your help!
Ok, I connected both PWM channels and now it works :-) reali PCM2PWM, sounds great! :)
Login or Signup to post a comment