Toshiba 3950

[randytsuch]

Over at Audio asylum, on the digital board, there are too many posts to count concerning the 3950/3960 CDP's.

They are cheap, 3950 is $60 at Best Buy right now, are supposed to sound reasonable stock, and are supposed to respond very well to mods and tweaks.

I had not visited here or AA that much recently, and I was somewhat surprised that there is so much on the 3950 there, and nothing here.

Seems like it would be a natural here, cheap to buy, and appears to make a good foundation for a modded CDP.

I bought one yesterday at BB, but I have not had a chance to unpack it yet. My plan is to let it burn in for a few weeks, and make sure it works OK, then start modding it.

It has a switcher PS, which I am sure is a weak point. The thing I like is all the rest of the electronics are on one board, no interconnecting cables to introduce jitter, and that board is supposed to have a ground plane. The ground plane, if true, is really surprising to me in a $60 CDP.

It uses a TI 1751 DAC.

Randy

[PrimeCase]

Randy
I picked one up 2 weeks ago and have changed the coupling caps in the audio path to black gate NX-Hi Q, the op amp to a BB OPA2604 (a ****** to solder) and several power supply bypass capacitors with 120uf Panasonic FC, all I need to do is identify the mute transistors and remove them and I'll be just about there
In all honesty is is a suprisingly good player, it balances it's compromises well. A very listenable player stock but certainly plays better music with decent coupling capacitors and a slightly more acomplished op-amp. well worth the $40 in modifications I spent.
Finally, I hear that it is a great transport and better than most CD player transports at any price...but I haven't verified this.

Kevin

[randytsuch]

Hi Kevin,
Thanks for the reply.
My player is unpacked, and burning in now. I bought a 2nd one, as a backup, while they are still available. Have not had good luck with my CDP's lately, so I wanted a spare one.

I am looking for a service manual for it, to help figure out what to do. Would like to start with the PS, then go to the audio board.

Randy

[PrimeCase]

A service manual wouldn't be a bad idea....for me the best part of the upgrade/mod was putting in better coupling caps........staggering improvement.

Kevin

[randytsuch]

Originally posted by PrimeCase
A service manual wouldn't be a bad idea....for me the best part of the upgrade/mod was putting in better coupling caps........staggering improvement.

Kevin

Did you change the caps between the DAC and opamp, and the ones after the opamp?

I was also wondering if the caps between the dac and opamp were really necessary, don't know how much dc offset the dac is putting out.

Randy

[PrimeCase]

the caps between the DAC and op amp are unavoidable as it has varying amounts of DC on the output (a rough form of class A anyone?) and yes, I changed the caps before and after the op amp

Kevin

[Davet]

I got caught up in the 3950/3960 hysteria about three weeks ago. I purchased a 3950 from BB for $60. I listened to it and was suprised how good it sounded right out the box. I set it on repeat fro 96 hours. I placed a few books on top of the chassis and then sat down to listen again. The unit mellowed some, but not to my liking. The sound stage seemed to be completely between the speakers. Although there was depth to the soundstage. The sound came from between the speakers and the midrange was "forward", but this aspect of the unit I liked.

I then impemented the AA Swenson mod using Dayton 0.47 MFD caps and CAT5 twisted pairs. I ran the wires from the audio board out thru the crack in the chassis and into a plastic travel soap container from Walmart. I mounted the caps and RCAs in the soap container, checked the wiring again, then turned it on for a listen.

I was, pleasantly, suprised upon listening, that the sound stage had broadened well beyond the width of my speakers. The "forward" midrange had retreated back into the soudstage. I really enjoyed the results gained from this minimalist tweak. I had all the parts on hand except the 65-cent soap container. I listened for a few days and then switched back to my standard player a heavily tweaked Sony CDP 390.

The 3590 compared to the Sony had close to the same breadth and depth of soundstage. Although, the Sony had the low level detail, gets a slight edge on the soudstage, air around the performers, localization and focus, and bass impact that the 3950 lacks. Overall the modified 3950 lacks focus.

NEXT: I am ordering the parts for the AA Vinnie mod which beefs up the capacitance in the power supply for the 3590. In, addition I am going to try the opamp replacment and the blackgate coupling caps. I want to up the capacitance at the ICs (ala Bobwire) over the capacitance used by Vinnie. I also plan to shield the ICs and ground the shields. I will experiment with dampening the chassis and transport, and experiment with various coupling/isolation techniques.

I have seen a lot of people slam this unit and I can see it has considerable merit and some drawbacks. The unit is a winner at any price and considering its actual cost it is a superb value.

[PrimeCase]

Dave
I'm using mine with a set of HD580's right now and out of the box it would get congested and fall apart at high signal levels, with the OPA2604 that problem disappeared, and numerous other niggles with it. The black gates are true to form and take a while to loose a rather disjointed character and settle down.
Soundstaging is a funny thing but to be honest it is fairly low on my list of priorities, I'd rather have a musically correct presentation rather than a spatially correct one, so I generally don't worry too much about it (that is what us "flat earthers" are like I guess). What really surprized me about this player is it's tune playing, sure it's not a Linn CD12 or a Naim CDX/CDS etc. but it makes you tap your foot and doesn't want to make you switch it off which is good going for a CD player at any price level, at $60 it's a bargain. And just like you I bought it on a lark just to see what all the fuss is about, I'm glad I did. I'll be adding some chassis and transport damping and call it good, musically it rates up there with far better players and is a lot better than my old Arcam Alpha 5+ (that cost me the equivalent of $900 8 years ago)

Kevin.

[randytsuch]

I found and ordered the service manual, but it was $50.

A $50 service manual for a $60 CDP , seems kind of wrong doesn't it.

But, I figure it will save me some time, so it was worth it to me.

They said a week or two to get it.

Randy

[PrimeCase]

Randy
I'll quite happily pay a few bucks for a photocopy of the main schematic......possibly help sweeten the cost of the manual a bit..

Kevin