Logitech Touch mods

Wayne1 · « **on:** 29 Apr 2010, 07:29 pm »

I have started on the first round of mods for the Touch.

The analog section sounds VERY good, but there is even better sound quality lurking inside.

Logitech did install some polarized, electrolytic caps in the output circuit. AKM, the manufacturer of the DAC chip used in the Touch, does say that the use of coupling caps are optional. I measured the offset from the chip and it was well within reasonable bounds.

I removed the caps. I also examined the way the chip was implemented There were a few things that could be change in the power delivery to the chip. I went also went ahead and dipped into my rapidly diminishing supply of small BlackGate caps and replaced the caps supplying the DAC chip.

There were a couple of other places that stood out that could use some power supply help. I carefully reassembled the Touch and put it back into the system.

OH MY! That coupling cap really was holding the sound of the Touch back. Just amazing transients now. I'll give the rest of my changes a few days to run in more.

My suggestion to all who own a Touch is to replace the stock power supply with a GOOD linear power supply. The next level would be to get some simple analog mods done. It really transforms the sound of a very good player.

highfilter · « **Reply #1 on:** 29 Apr 2010, 08:43 pm »

Great information. I am thinking about getting a Touch - what good linear power supplies do you recommend?

poseidonsvoice · « **Reply #2 on:** 29 Apr 2010, 08:50 pm »

You haven't listened to the unit as a pure digital source with an external dac yet right?

Anand.

Wayne1 · « **Reply #3 on:** 29 Apr 2010, 09:07 pm »

Anand,

Not as of yet. I am expecting an EE DAC tomorow or Monday. I'll post my thoughts then.

Right now the Touch does sound very good, but it is a little "thin". I feel it would benefit from a tube output stage.

highfilter,

If you can fine one, the ELPAC WM220 is a very nice power supply. It will need the connector changed. I offer mods for that unit. The power supplies I offer are all very good sounding but on the expensive side. I do feel you get what you pay for.

mchuckp · « **Reply #4 on:** 5 May 2010, 10:45 pm »

Wayne,

I'm running a SB Touch in stock form into the new W4S DAC-1. Does your power supply you have on your website for the Duet work with the Touch? If so, is this an upgrade you'd recommend for me?

Thanks,
Mike

Wayne1 · « **Reply #5 on:** 5 May 2010, 11:54 pm »

Mike,

Sorry, I have a few different power supplies on my website. I would suggest, at a minimum, to get a good linear power supply. On the low end of the cost scale, if you could find an ELPAC WM-220, and send it to me for mods, that would be a good thing

The Standard Power Supply I have on my site is quite a bit better but more expensive. It can be built for a 5 volt output for the Touch. It runs about $500.00

Standard Power Supply

It can be built into a bit of a better looking case

I also offer The ULTIMATE Power Supply for use with the Touch.

In my listening, with the EE DAC, using a linear power supply with the Touch offers a major improvement.

DZetye · « **Reply #6 on:** 14 May 2010, 12:29 am »

Wayne,
Are their any updates on mods (digital) for use on the Touch besides the power supply that would improve it for use with an outboard DAC?

Wayne1 · « **Reply #7 on:** 14 May 2010, 02:42 pm »

I have not been able to come up with any digital only mods, yet.

I am very satisfied with the analog improvements. I will be adding the analog only mods to the website next week.

The Touch does need some time to settle in. Roughly 2-3 weeks. The power supply will make some fairly major improvements to the sound of the unit. The better the PS, the better the sound.

poseidonsvoice · « **Reply #8 on:** 17 May 2010, 01:36 pm »

Wayne,

What's the voltage and current requirement for the Touch?

Have you experimented with any other type of 4 pole capacitor other than Jensen, like the DNM types?

Thanks,
Anand.

Wayne1 · « **Reply #9 on:** 17 May 2010, 10:14 pm »

Anand,

The Touch wants 5 volts and 2 amps. If you use an external HD plugged into it, it will want at least another amp.

I have not tried the DNM caps. They look rather interesting.

Wayne

Mariusz · « **Reply #10 on:** 17 May 2010, 11:26 pm »

Just curious
will Parts Express $15 power supply work with Touch?

Wayne1 · « **Reply #11 on:** 17 May 2010, 11:49 pm »

The PE supply will not work in it's stock form. It would need some resistor values changed so it can put out 5 volts. It will also run a bit on the wrm side. I would not suggest it if you plan to run a USB drive from the Touch.

For 5 volts, the ELPAC WM-220 might be able to be found on E-Bay for a good price. It will need a different connector put on the DC cable.

The ELPAC will sound better after a rebuild, but it should be an improvement over the stock switcher.

poseidonsvoice · « **Reply #12 on:** 17 May 2010, 11:57 pm »

Quote from: Wayne1 on 17 May 2010, 10:14 pm

Anand,

The Touch wants 5 volts and 2 amps. If you use an external HD plugged into it, it will want at least another amp.

I have not tried the DNM caps. They look rather interesting.

Wayne

Is that the same current and voltage requirement of the SB3?

Anand.

Wayne1 · « **Reply #13 on:** 18 May 2010, 07:16 pm »

Anand,

Running the Touch from a remote server, the current draw is about the same as the SB3.

poseidonsvoice · « **Reply #14 on:** 18 May 2010, 09:03 pm »

Quote from: Wayne1 on 18 May 2010, 07:16 pm

Anand,

Running the Touch from a remote server, the current draw is about the same as the SB3.

Great, that means I could use my Katalyst power supply that I use on my SB3 right now.

I need to look and see what the fuss is all about for the Touch first, must be the interface or something!

Anand.

Wayne1 · « **Reply #15 on:** 19 May 2010, 01:34 am »

Quote from: poseidonsvoice on 18 May 2010, 09:03 pm

I need to look and see what the fuss is all about for the Touch first, must be the interface or something!

Anand.

That and the 24/96 capability. If you get the right recording, it sounds SO close to good, high end vinyl. I'm talking $20,000.00 and better vinyl rigs playing 180 gram 1/2 speed masters at 45 rpm.

Unfortunately the 24/96 catalog doesn't come close to the 16/44.1 catalog. What is out there does sound really good. I hope to have a modded Touch playing into a modded EE DAC at RMAF.

Please put Lou Hinkley and me on your must listen list if you are planning to attend. Lou will have his latest Ulysses speakers with all film cap crossovers powered by Atma-sphere amps. He will be introducing a subwoofer along with a collaborative project.

We will have vinyl to compare with the digital source. There will be very few recordings that are both issued on vinyl and 24/96 but we hope to have a couple. It should be fun.

kyrill · « **Reply #16 on:** 21 May 2010, 11:21 pm »

Quote from: Wayne1 on 19 May 2010, 01:34 am

That and the 24/96 capability. If you get the right recording, it sounds SO close to good, high end vinyl.

I'm talking* $20,000.00 and better vinyl rigs playing 180 gram 1/2 speed masters at 45 rpm.Is this the analogue out or the "unmodded s/pdif out?
this SQ is ( to my ears) the ultimate high end. If the modded analogue can reach this, doesn't it mean the Touch is ultimately high end price no object?
Unfortunately the 24/96 catalog doesn't come close to the 16/44.1 catalog. What is out there does sound really good. I hope to have a modded Touch playing into a modded EE DAC at RMAF.

Please put Lou Hinkley and me on your must listen list if you are planning to attend. Lou will have his latest Ulysses speakers with all film cap crossovers powered by Atma-sphere amps. He will be introducing a subwoofer along with a collaborative project.

We will have vinyl to compare with the digital source. There will be very few recordings that are both issued on vinyl and 24/96 but we hope to have a couple. It should be fun.
*If you don't mean the analogue out as you also suggest a modded EE dac implying the digital out of the touch. does this mean the SQ of the digital out into a very good DAC reaches the 20.000 dollar analogue rig, if yes is this the unmodded digital out as you state a post before you have not yet concentrated on the digital out mods?

Gopher · « **Reply #17 on:** 22 May 2010, 03:41 am »

Quote from: Wayne1 on 19 May 2010, 01:34 am

That and the 24/96 capability. If you get the right recording, it sounds SO close to good, high end vinyl. I'm talking $20,000.00 and better vinyl rigs playing 180 gram 1/2 speed masters at 45 rpm.

I must admit, the touch/minimax (stock) combo is quite nice, but my vinyl rig carries a retail of a little more than half that and it is on another level.

Your modifications to the minimax must really be something to consider! I'll be interested to see how they develop.

Wayne1 · « **Reply #18 on:** 22 May 2010, 05:59 am »

I am sorry I have not made myself more clear.

Currently, I am listening to the Touch through a slightly modded EE DAC. When playing certain 24/96 material it does rival most of the vinyl I have heard. I do own a Teres 200 series TT. I have heard it with a very nice modded Rega arm with a Shelter 801 cart into a Hagerman Cornet and Trumpet phono stage. The Touch with Bolder PS and modded EE DAC is very close.

The full mods on the EE DAC with exceed the sound quality of my analog rig.

I have not spent as much time as I should listening to the analog modded Touch. It is quite a bit better than stock, but not as good as feeding into the modded EE DAC.

As far as high end, price no object, the Touch will fall short. At this point it is limited to 24/96. I have heard some of the very few Reference Recordings albums at higher sampling rates. They do sound better, without a doubt. There are maybe a dozen readily available recordings in this format. Perhaps, in time, there will be more. Perhaps the Touch will be able to play these recordings back in their native format. But for now, the Touch falls just a bit shy of the ultimate digital playback.

For 99.94% of people, the Touch will deliver everything they could want.

kyrill · « **Reply #19 on:** 22 May 2010, 06:34 pm »

Hi Wayne

Do you expect there is still room for the s/pdif out of the
Touch to be improved by mods you can think of?

K