[mcgsxr]

I have shipped one of my Teac Tripath amps off to Wayne at Bolder Cables, who is to do some preliminary mods for evaluation for me.

Stay tuned for the goods on this emerging venture!

Mark in Canada

[albee]

Anyword yet as to what can be done to the Teac box?  I've just been breaking mine in with movies.  I have yet to listen to CD's.  

One thing:  I had a dickens of a time connecting my Mapleshade speaker wires to the posts.  I finally settled on the center/right channels for convenience and noticed that the center channel seems to have much more gain than either the left or right.  Did you notice that?  I think getting the center board and posts out of the way would be a good move.

[mcgsxr]

The Teac hit the mail from Canada to Colorado last Friday, so I would think that Wayne will get his first look at it on Monday - so, no word on what he plans to do, as yet.  I know that most of his efforts involve changes to input and output connections (that might help with your speaker wire concerns) and I am sure that the power supply will get a good once over.

Beyond that, I am the wrong guy to speculate, just the right guy with one to spare!

I have not had any problems with the speaker binding "posts" since I just added some banana plugs, otherwise I couldn't work that out either.

As for the gain issues, I am not sure, but I did ask Wayne to remove the gain pots from the signal path altogether for me, since I doubt they are preserving the signal well - not claiming that they are doing bad things, but I don't imagine that they are of the highest quality, and I will always use a preamp, so I don't need them.

I found that the treble really relaxed after an 80 hour straight break in, that ended about 120 hours of break in for me.  Since then, I have been pleased to sit down to smooth sound, and drink in the music.

Once Wayne waves the magic wand, and advises what can be done, for what dough, I will pick from the menu, and I will certainly report back what I hear.

One interesting thing is that I think it sounds better NOT passively biamping my Totems - with the one amp (using just the L and R channels) I find the centre (sorry, Canuck spelling eh) fill stronger, and the soundstage wider.

I will have to experiment with using the two amps (C channel on each) versus just using the L and R of one amp, versus using L&R of each amp... Got my work cut out for me in THAT thread...

Oh yeah, it sounds better in black...

Mark in Canada

[albee]

I have about eight pairs of bananas laying around but bananas can really soften the sound of Mapleshade wires.  Mapleshade sez it and so do I.

I may paint mine red or green.  Red for more lively and green for more relaxing--time will tell.

[TheChairGuy]

Hope Wayne can work his magic for ya' on the TEAC, Mark.

Do report back with results. Eh?  

[Dmason]

I will be very interested in what becomes of the Teac once in Wayne's World. It really is a nice product. A total sleeper, IMO.  Even with the minor tweaks like a good PC, shielding, and isolation, (Tripath is highly susceptible to both EMI, and vibration,) it really shines. I agree with the notion of more sensitive speakers of over about 91db, and Tripath watts when properly aspirated are pretty Big Watts.

I am using mine with a pair of freshly breaking-in 92 db Fostex FX200's. These things are everything people are saying they are, and the best is still yet to come. Without the crossovers, this becomes a very classy little active system. T- amp speaker interaction with Fostex speed and resolution.... Synergy. I chose the recommended 25L cabinet and porting, right off the company site, and it works fantastically well. Kudos to Fostex for the TLC that went into the FX series speaker, and to Teac for coming up with the $99 baby "monoblocks," it is just a great little amp.

[mcgsxr]

Hey Dmason, what, did you clone my mind through a PM or something?  I JUST started pestering Ed Shilling about his full range, rear horn loaded Fostex speakers...

Hopefully Wayne can have some affordable fun with my amp, and since he has a set of the Horn Shoppe Horns, he intends to run them with my amp, once the mods are done, to give me a preview of the combination I am thinking about trying to find the $$ for...

Mark

[albee]

Dmason:  No disappointments at frequency extremes with the FX200's?  How much is that driver going for these days?

[GBB]

I popped into NYC earlier this week and picked up one of these amps at J&R music..  For $100, what does one have to lose.  I hooked it up and it didn't sound bad but it also didnt' sound great after playing for 24 hours or so.  Being an inveterate tweaker, I opened up the amp and had a look around.  

Its pretty well built and actually has two complete stereo amp boards.  One is used for the L/R channels and the other board only uses one of the two channels for center.  An interesting experiment would be to build a killer power supply and rewire each board as bridged mono.  The Tripath website has the datasheet for the 2050 chips which are used in this amp and show how to rewire things.  However thats a lot more work and not what I did this time.  

Instead I just looked at the input coupling caps to see if that was an issue.  It turns out that the amp uses cheap 2.2uf electrolytic caps and that it also has two sets of coupling caps - one set at the input volume control and another set on the amp boards.  These are effectively in series and reduce the effective coupling cap from 2.2uf to 1.1uf.  This might explain why some find the bass slightly light.
The easiest change is to eliminate the coupling caps on the input board by shorting them out and to change the caps on the amp board.  I did this, using some Xicon 3.3uf film caps I had and it seems to have made a very nice improvement in the sound.  Much more transparent sound, cleaner highs, etc.  Highly recommended for the adventurous.

---Gary

[mcgsxr]

Welcome to Teac Tripath land GBB, and thanks for sharing your findings about tweaking this little beast.

Yeah, the 2050 chip can be bridged to provide around 75wpc to 4ohms, and since there are 2 full chips in the chassis, I guess a 2x75w amp could be created, but as you mention, the stock PS is not up to the task.

Interesting point about the 2x coupling caps, I did not notice that (mind you, I am no DIY amp person either...) and it is interesting to note the changes when you take a set out, and mod the remaining ones.

More transparency, and cleaner highs eh?  What about the soundstage or the lower registers, any changes to not there?

What speakers do you use?  

Mark in Canada

[Dmason]

albee/Mcgsxr,

It is way too early to tell what the Fostii are going to sound like because they take "forever" to break in. No one with the FX200 needs a tweeter, unless it is to add that very last bit of air, if I ever add one, Fostex has an obscure but excellent ribbon tweeter , -oh yes they do- and I would mount it on the back of the cabinet. the highs already are fine. In fact, if I find the highs noticeably rolled off, it may as likely be as a result of the amp.

The FX & F (AlNiCo) series are spectacular works of industrial art, and priced at $150 and $375 respectively. Just beautiful, shining examples of care, attention, and love of art in the service of music. No shit: see one, and you will agree. For bass, the 25L BR cab should yield an F3=45Hz+-, which is plenty. In the smallish back room, it is absolutely killer, and loads the room in such a perfect way. I mounted the speakers on the narrow side of the cabinet like Louis does, with a vertical 3/4" roundover, and mounted the port on the back for some room gain.

This weekend I am sanding out the cabinets and they are going to a buddy's paint shop for a few coats of black anthracite + acrylic, the paint is courtesy of a BMW he is painting, so it is THAT type dark "anthracite" flip-flop if you are familiar, --perfect looking auto finish to go with the pearlescent cones, shiny dust cap, and brushed alloy flange with sintered ends, on the FX200. This will be one of the nicer looking speakers out there. I cannot wait.

I am looking forward to the conclusions on what works best with the Teac mods, and go from there. Tripath and Fostex make for a new synergistic legend in audio, just ask Uncle Ed

[GBB]

I've been using these amps in a biamped system - Edgarhorns with TAD 4002 crossed over at 500hz and some homebrew transmission lines below.  I drive the transmission lines with an old Threshold S300II and have used a single ended VT25 amp or a class A 10W solid state amp.

I tried the TEAC out driving the Edgarhorns so my comments really relate to the mids and highs only.  I'll try it out in another system with full range speakers down the road.

---Gary

[Occam]

GBB & Mcgsxr,

The Tripath 2050 chip provides 2 channels, each of which is already bridged, i.e. each of the 2 channels is composed of 2 half bridges driven 180degrees out of phase with respect to each other. This is why the sukka works with a single rail supply and you can't take the 2 channels and bridge them together.

Yes, you can eliminate the first capacitor/channel that is in front of the level control (potentiometers get noisey when fed dc...), or if you are sure the source feeding it has no DC component. You cannot eliminate the capacitor in front of the amplifier itself as it is there to block the +2.5v that the chip biases itself with. This is required for proper operation of the chips inverting opamp at the input. If you eliminate the level control and are sure your source is capacitor coupled, you can eliminate it, at your own risk.  A source with a servo circuit, as opposed to a cap, will not allow you to do this.

Please read the data sheet carefully, and understand what is going on....

Because the amplifier input is biased at +voltage, an electro cap can sound quite good in this position. Certainly, a better film cap, or a BG N electrolytic (if you're prepared to wait forever and a day for it to break in)  would be an improvement, but simply bypassing this input cap with a ROE MKP1837 .01uf (available at Mouser) will offer tremendous improvement.

[ooheadsoo]

The teac has 3 channels, nominally though.  L, R, and Center.  There are two independant amp boards.

[GBB]

Occam and others,
You can find the datasheet for the chips used in the TEAC (Tripath 2000 and 2050 chipset) here:
http://www.tripath.com/downloads/TK2050.pdf

Page 6 shows a typical circuit which is similar to what is done in the TEAC.
Page 7 shows how the two amplifiers in one chipset can be bridged.  Quoting from the datasheet, page 14:

For stereo mode operation, the TK2050 is a dual full bridge. For parallel mode operation, the TK2050 can be configured as a single full bridge with double current capability by connecting the CONFIG pin to the VDD pin of the TP2050. Please refer to the Application/Test Diagram for parallel operation.  

-------end quote--------

Regarding the danger of removing the input coupling capacitor, its pretty low and ideally one would remove the entire level control and wire directly from the RCA inputs to the amp boards.  The input cap for the amp board is required and should be as high quality as one can afford.
Since space is tight on the amp board, the simplest thing might be to put a high quality capacitor right at the RCAs where there is more room.

---Gary

[mcgsxr]

For those interested:

Wayne has finalized his mods for this player, and when the parts arrive, the work will begin.  I imagine that I will be breaking the modded Teac in, in about 2-3 weeks, depending on travel time etc.

I will leave it to Wayne, to outline what his mods entail, I am sure I would make a mess of trying to explain it...

Mark in Canada

[Wayne1]

Here is a quick photo of the changes to the back panel.



More to come...

[mcgsxr]

http://www.audiocircle.com/index.php?topic=13938

The work approaches completion, and I am getting more excited!

Mark in Canada