[tortie]

Great job! What are your additional mod plans for the future on that CDP? I sense more upgrades to come

 

[rsaavedra]

Quote:

Originally Posted by tortie Great job! What are your additional mod plans for the future on that CDP? I sense more upgrades to come

For me possibly replacing that fat cap only, but that would need to be recommended by someone more experienced with circuits than myself. I only have a hunch it might be worthwhile replacing it. Other than that not much more for me. I think I wouldn't want to change that opamp again, still healing bruises and fractures from the tough fight

A case replacement sounds interesting but too involving right now for me. I would rather do case work when building the Dynahi.

 

[ServinginEcuador]

As usual, your work looks great and is improving Raul. Great job on the op amp soldering. Once your confidence and skills are higher you'll be able to start tackling bigger and more complicated jobs.

 

[agile_one]

Quote:

Originally Posted by rsaavedr Mods completed successfully!!!!

Bravo, Raul!

Great job, and terrific descriptions and pictures of this further enhancement to the Tosh.

 

[smeggy]

This thread is a definate keeper for when my modding starts, lots of references and inspiration to not screw it up.

 

[rsaavedra]

Thanks very much guys for the encouraging comments!

Cheers,
Raul

 

[rsaavedra]

Itzbitz, do you have any thoughts on cap 905? A guy in Audioasylum who saw the pics on this thread is recommending me to replace that cap also since allegedly it works together with 903 on the DAC:
http://www.audioasylum.com/audio/dig...ges/87340.html

903 got replaced with a Blackgate, but not 905, given that Rossi simply didn't have it in his mods, and I followed those exactly. I have no idea about the circuit of the Toshiba, what those caps are jointly doing on the DAC, or what each leg of that specific DAC does/expects etc.

 

[rsaavedra]

Rossi himself emailed me saying he never replaced 905, but suggests that I give it a try with a Blackgate cap equal to the one used for 903, as suggested. If anything it should improve even further, not deteriorate the sound. In case anyone is interested, according to him:
905 is tied to the Vcom terminal of the 1751 DAC.
903 is tied to the Vcc terminal (input voltage to the DAC).

I'll be changing that cap soon, will order it together with the caps for the Dynahi.

 

[ITZBITZ]

Okay, round two completed.

First round was the power supply mods, Panasonic FC on the audio board and the OPA2604. First round improved the bass but the high-end was still a bit grainy. Midrange was much improved in terms of overall tonality.

Second round was the black gates in the recommended spots, plus I replaced 904 and 905 with Panasonic FC's as well. At the same time, I replaced the OPA2604 (yeah, already bored with it) with a pair of OPA627AU's on a BrownDog adapter (2xSO8->SO8).

Results? I have never been one to believe the "blown out of the water" hyperbole associated with these type of modifications. However, the difference is VERY noticeable, particularly in the treble band. The grain is completely gone with very clear, detailed high frequencies. Symbols are clean, detailed and not gritty or mushed into a "squishtt" sound at all. Very quick, very accurate and a serious improvement over round one.

In amplification, I can hear an audible difference between the OPA134 and the OPA627. The OPA2604 is supposed to be close to the 134, so I'm guessing the differences are comparable. The bass is rock solid, tight and not overdone. And the midrange is amazing, female vocals come through sounding oh-so-sweet. Separation sounds excellent, off-center vocals sound well focused and defined instead of just off-to-the-side.

Amplification is via my high-end PPA with stepped-attenuator and OPA627 chips into Phil's diamond buffer, so the output stage is very complimentary to the source.

Sadly, my computer isn't going to cut it as a source unless I find a comparable output stage. The Toshiba is now dead silent in the background, likely due to the OPA627 having a 110dB PSRR compared to the 70-80 of the 2604.

So yeah, don't wait, order a BrownDog and get a pair of OPA627AU, just tell Phil that Chris sent you.

 

[rsaavedra]

Great info Itzbitz, man you are pushing me to another fight with a tiny opamp replacement it seems.

 

[ITZBITZ]

Glad I'm not the only one up late. I'm about to sit down for another hour of listening before bed, the storm has passed so I don't have to worry about thunder interrupting my listening pleasure.

I listened the player right before I changed the op-amp and noticed the change immediately. Listening to the same passage within a short amount of time makes it easy, particularly since I listen to the same song quite often. I'm not sure what I'm going to do to my Sonica now to see if it can catch up. I guess it might be time for the old Emu 1212m if the AV710 doesn't work out.

 

[rsaavedra]

So Itzbitz, that browndog adapter has to be soldered directly on the SMD pads where the opamp would normally be soldered on?

PS. Also, I now notice your 1st round of changes included the OPA2604, but not the blackgates, wonder if that's related to that grain you spotted. Rossi indicates the installation of the 2604 should better be done together with the blackgates because they allegedly have some special synergy.

 

[ITZBITZ]

This is the ticket right here:



It solders to the board after you've put the two op-amps on it.

I've used black gates before to replace the stock caps on my Sonica and didn't notice the type of change as I noticed with the op-amp switch last night. I had previously replaced the stock caps with Panasonic FC's until my black gates arrived, so I wasn't using the stock caps before.

FYI, after a couple of hours of listening last night to very familiar music, I must say that the entire range is now very sweet, clear, not overly detailed, no splashiness at all, just very musical sounding. In short, I think I'm done modding and completely satisfied with the 3950 in its present form.

 

[rsaavedra]

Itzbitz thanks a lot, I'll try your variation on these mods. I'm liking the sound of my modded Tosh a lot already, if it can get even better, I should implement special measures to ensure player's longer life expectancy. Planning to get another 3950 and just store it in a closet, keeping it for spare parts and backup for the future, especially for the transport.

 

[tortie]

Maybe after you have changed the opamps, you guys can try these out

Clock upgrade