Go Back   Home > Forums > >

Headphone Systems Everything to do with Headphones

High performance OPA1602 + TPA6120A2 Composite Headphone Amplifier
High performance OPA1602 + TPA6120A2 Composite Headphone Amplifier
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools
Old 13th December 2020, 04:41 AM   #41
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC (Virginia)
High performance OPA1602 + TPA6120A2 Composite Headphone Amplifier
Well, I was referring to something like this and no need to include it in the feedback loop.

TPA6120 Headphone Amplifier Board HiFi TPA6120A2 Double Channel Headphone Amp Tu | eBay

Click the image to open in full size.
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio
  Reply With Quote
Old 13th December 2020, 11:29 AM   #42
BamboszeK is offline BamboszeK  Poland
diyAudio Member
 
BamboszeK's Avatar
 
Join Date: Jun 2012
I agree with Chris. My amplifier or very similar Topping L30 isn't exactly best option for modding. Feedback in composite amplifiers needs precise tuning, otherwise even small changes can make them unstable.
By replacing first opamp in composite amp with discrete one, you would basically need to redesign whole amplifier. Even then you can't be sure about stability. I highly doubt that discrete opamp manufacturers provide SPICE simulation models.
If you find some kind of distortion sound pleasing I would suggest another way of introducing them to signal path. Personally I prefer faithful playback gear and all manipulation done in DSP.
If I want something that "render" music instead of reproduce it, I build guitar effects and tube amplifiers
  Reply With Quote
Old 13th December 2020, 11:42 AM   #43
Mark Johnson is offline Mark Johnson  United States
diyAudio Donor
diyAudio Member
 
Mark Johnson's Avatar
 
Join Date: May 2011
Location: Silicon Valley
High performance OPA1602 + TPA6120A2 Composite Headphone Amplifier
Thanks for mentioning the L30, ggetzoff. I ordered one from Amazon and look forward to plinking around with it.
  Reply With Quote
Old 16th December 2020, 05:03 PM   #44
ziga90 is offline ziga90  Slovenia
diyAudio Member
 
Join Date: Feb 2015
Location: Ljubljana
Hi Bamboszek,


Can you share your BOM? I will try to prepare shematic for PCB but in case of any issues on the way, do you have a spare PCB to sell?


Is there any major differences between Topping L30 and this amp? Headphone set is Sennheiser HD598.


I would use my HP lap top as audio source for this amp, is there anything that needs to be adjusted?


Thank you.




Kind regards, Ziga
  Reply With Quote
Old 16th December 2020, 06:05 PM   #45
BamboszeK is offline BamboszeK  Poland
diyAudio Member
 
BamboszeK's Avatar
 
Join Date: Jun 2012
I still have a few spare boards. No exact BOM with part numbers as I ordered lots of parts for prototyping from different vendors.
PCB layout for amplifier with such high speed device as TPA6120A2 isn't trivial.
L30 is more or less similar. Much lower input impedance, slightly different feedback/compensation and added output relay.
12dB of gain should be plenty even for laptop level output.
  Reply With Quote
Old 21st February 2021, 12:59 PM   #46
MASamplifer is offline MASamplifer  United States
diyAudio Member
 
Join Date: Nov 2019
Location: Tucson, AZ
Good morning all,
I was not actually aware all this composite amp work using the TPA6120A2 was going on. In parallel, talking with Jan Didden, I had embarked a similar trek that now show up on page 42 of the March 2021 AudioXpress. In the early Comlinear days as apps manager, we were doing a lot of composite amplifiers as the only source for high voltage CFA (1985 to 1990 about). Yes, the ADSL (or more generally differential wireline drivers) are intrinsically very low distortion of necessity. That was my main area for many years - all of those standard DMT (discrete multi-tone) - think of them as little radios in 4kHz slices (for xDSL). The key test for linearity is called and MTPR test - multi tone power ratio - the lineal descendent of the old microwave NPR test (noise power ratio). Essentially, you fill up the test spectrum with carriers with a notch of no power and look at how much those carriers fold into the notch (a comprehensive intermodulation test). Intersil actually was the dominant line driver supplier for a lot of this and as apps manager we did publish one of the very few public discussions on these issues - this largely came out of a more interesting development I was doing as a 14bit 500MSPS digitizer board we were doing to highlight the somewhat incredible ISL55210 FDA. In any case, those 2012 article have apparently migrated all over the place, but here I found part 1,
Linearity testing for G.hn PLC line drivers, pt.1

and then part 2 somewhere else - pretty odd actually.

https://www.eetimes.com/linearity-te...rivers-part-2/

The essential point is, yes, you are going in the right direction with dual CFA ADSL line drivers for low distortion, high output, audio.
  Reply With Quote
Old 23rd February 2021, 07:28 PM   #47
BamboszeK is offline BamboszeK  Poland
diyAudio Member
 
BamboszeK's Avatar
 
Join Date: Jun 2012
Thanks for pointing out. Looks like I need to get my hands on newest AudioXpress and see your results. What input opamp did you used?
I've actually considered some Renesas (Intersil) parts but if I recall correctly there was something missing for this particular application as composite headamp.
  Reply With Quote
Old 23rd February 2021, 07:40 PM   #48
chris719 is online now chris719  United States
diyAudio Member
 
Join Date: Jun 2004
Location: Connecticut
High performance OPA1602 + TPA6120A2 Composite Headphone Amplifier
Quote:
Originally Posted by MASamplifer View Post
Good morning all,
I was not actually aware all this composite amp work using the TPA6120A2 was going on. In parallel, talking with Jan Didden, I had embarked a similar trek that now show up on page 42 of the March 2021 AudioXpress. In the early Comlinear days as apps manager, we were doing a lot of composite amplifiers as the only source for high voltage CFA (1985 to 1990 about). Yes, the ADSL (or more generally differential wireline drivers) are intrinsically very low distortion of necessity. That was my main area for many years - all of those standard DMT (discrete multi-tone) - think of them as little radios in 4kHz slices (for xDSL). The key test for linearity is called and MTPR test - multi tone power ratio - the lineal descendent of the old microwave NPR test (noise power ratio). Essentially, you fill up the test spectrum with carriers with a notch of no power and look at how much those carriers fold into the notch (a comprehensive intermodulation test). Intersil actually was the dominant line driver supplier for a lot of this and as apps manager we did publish one of the very few public discussions on these issues - this largely came out of a more interesting development I was doing as a 14bit 500MSPS digitizer board we were doing to highlight the somewhat incredible ISL55210 FDA. In any case, those 2012 article have apparently migrated all over the place, but here I found part 1,
Linearity testing for G.hn PLC line drivers, pt.1

and then part 2 somewhere else - pretty odd actually.

https://www.eetimes.com/linearity-te...rivers-part-2/

The essential point is, yes, you are going in the right direction with dual CFA ADSL line drivers for low distortion, high output, audio.
Just wanted to say that I've come across several of your articles and posts on TI's forum and they are always top notch.
  Reply With Quote
Old 26th February 2021, 09:22 AM   #49
JensH is offline JensH  Denmark
diyAudio Member
 
Join Date: Jul 2009
High performance OPA1602 + TPA6120A2 Composite Headphone Amplifier
Hi Michael,

I have read your interesting article in the March 2021 edition of AudioXpress.
A couple of things surprised me a bit.

In your simulations you seem to use a purely resistive load (32 ohm). Wouldn't it be necessary to check the stability with a complex load, at least with a capacitor in parallel with the 32 ohm ?

You do mention the "relatively low input impedance". In my view the low input impedance puts some tough requirements on the preceding stage if you want to maintain the very low distortion.
Have you tried a non-inverting configuration, similar to the one Bamboszek has used ? Do you have an opinion on the performance of the one from Basboszek (and perhaps the Topping L30, using the OPA1612 and a slightly different compensation compared to Bamboszeks) compared to your inverting design?
  Reply With Quote
Old 26th February 2021, 04:19 PM   #50
BamboszeK is offline BamboszeK  Poland
diyAudio Member
 
BamboszeK's Avatar
 
Join Date: Jun 2012
One of things I wanted to examine was inverting vs non-inverting configuration effect on distortion. That was reason why I decided to try OPA1602. You probably seen those posts, but anyway:
New Audio Op Amp - OPA1622
New Audio Op Amp - OPA1622
New Audio Op Amp - OPA1622

I already reached performance cap of APx525 so didn't bothered with inverting topology as higher input impedance and preserved absolute polarity is rather useful. But inverting topology is indeed worth trying if we want to squeeze last dBs of THD.

Regards,
Miłosz
  Reply With Quote

Reply


High performance OPA1602 + TPA6120A2 Composite Headphone AmplifierHide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
High Performance Class A Current Feeback Headphone Amplifier monty78pig Headphone Systems 14 12th November 2015 01:01 PM
HIGH performance HeadPhone amplifier OUTONE Stee Headphone Systems 3 10th February 2015 06:27 PM
Huginn, High performance, Class A, Lateral FET headphone amplifier Neutrality Headphone Systems 11 7th November 2013 07:29 PM
Group Buy: QRV09 Ultra High Performance Headphone Amplifier peranders Group Buys 75 24th March 2013 09:54 AM
Ultra high performance headphone amplifier QRV09 peranders Solid State 121 25th June 2011 08:10 AM


New To Site? Need Help?

All times are GMT. The time now is 01:43 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki