[rhing]

Nice desktop setup Matt. I don't use power conditioners. My multi-outlet strip is a heavy gauge Wire Mold strip that I had purchased on the recommendation of a Naim Audio. I do have a Furutech duplex wall outlet and I use decent, but not terribly expensive power cords from Zu Cable and Element Cable. Most of my interconnects are DIY tri-braided Mundorf Silver-Gold wire cables that are comparable to Kimber KCAG Silver interconnects. My phono cables are all based on shielded Cardas quad cable. I use Switchcraft Gold-plated Copper alloy RCA connectors in all my DIY interconnect cables. I mention all this, because I believe that cables can be the weakest link in any system. 

I highly recommend that you replace the 22AWG power cable connecting your power supply to your TPA amp with something using at least high quality 18AWG to 16AWG wire. If you want something more energy efficient than the Astron RS-12A, then get a Mean Well 150 watt SMPS from Jameco Electronics and make a good DIY power supply using a good IEC AC inlet, Littelfuse fuse holder and Switchcraft 2.1mm x 5.5mm threaded DC power connector.

[Markvdv]

Very nice Matt! Those speakers will be great. I am very satisfied with an older Mark Audio type, strange thing is they really do keep improving with hours, and you can compare like me to other speakers in house to verify that.

12V PSU is like in caraudio, they have simple formula for size of DC wires I vaguely remember. I read your post about comparing the psu and power conditioner, I now feel that could be part of it. I did notice a lack of real low frequency with using one 6A instead of 2 6A bricks befor, I would think your 2A would also lack, but those frequencies might be impossible to hear anyway at 1 meter distance from speaker, not sure, I don't hear them close to my speaker, only when I get 3.5/4 meters from speakers, the distance could be room related too, but there on low level too (I don't listen loud) lowest frequencies went missing with one brick.

[Markvdv]

SMSL looks very interesting. So they actually seemed to have used the small smd elco's near inductors just for bypass/decoupling/filtering, too small for bulk reservoir function. Oscon replacement might actually be a little too expensive component for them to use as standard here, were the 47uF's  Panasonic? Sales pic shows old style elco's.

There might be a PLIMIT circuitry there? What do you think ringh, there seem to be more then just 2 resistors for gainsetting, 2 more to pins there would be plimit, or are the extra resistors actually in signalpath left and right channel?

[Poultrygeist]

If you heard what the Astron does for your TPA amp, you wont worry about putting it in a case.

Here is a Ten Tec that ends less than 24 hours and the bid is only $20.

http://www.ebay.com/itm/Ten-Tec-937-11amp-power-supply-/181426194869?pt=US_Radio_Comm_Device_Power_Supplies&hash=item2a3dd809b5

Now you all have me thinking of a smaller 3116 case that's more integrated with the Astron attaching from either the top ( piggy back style ), the bottom or maybe from the side.

[OzarkTom]

Now you all have me thinking of a smaller 3116 case that's more integrated with the Astron attaching from either the top ( piggy back style ), the bottom or maybe from the side.

As another AC'er here said, the Astron gets fairly warm. You might not want your amp touching the Astron.

I see that Ten Tec 937 went for less than $45 including shipping. Did you get it?

[Poultrygeist]

As another AC'er here said, the Astron gets fairly warm. You might not want your amp touching the Astron.

I see that Ten Tec 937 went for less than $45 including shipping. Did you get it?

No.

The 3116 wouldn't be touching but residing in it's own small case attached to the Astron. With limited shelf space I lack room for big bricks hanging off the back or large separate power supplies.

[trackball02]

Poultrygeist, I got the Ten Tec that you mentioned on ebay. Thanks for the tip. Not a bad price.

It is going to power my newly acquired 3118 amp.
http://www.shenzhenaudio.com/smsl-sa-36a-pro-20wpc-tpa3118d2-digital-amplifier-power-adapter.html

With the stock power supply, I thought that the amp is good for the money, but not great. I'm very curious on how the Ten Tec will sound.

I'm running this amp with the volume control turned all the way up, since I've have a prreamp. Is there a possibility that the volume control causes degradation? Can and should it be bypassed? I have not opened the case yet to look inside to see if it is possible.

[wired4sound]

Thanks for the explanation. I was able to figure out the negative/positive on the terminal and the amp is now working great.

wired4sound, no your board isn't the same, but is your board green? (most are blue) doesn't matter btw, top of 4 point speaker connector is a plus for originally right speaker, but most chinese amps change that to left, the minus is below that, another channel plus beneath that one and finally a minus for speaker again, originally left but on chinese board probably right channel:)

if in doubt follow traces + right originally top output speaker connection like in picture ebay goes to third pin from top on chip (or 4th pin)

minus left channel = bottom speaker output should go to 4th or 5th pin on chip from bottom (in ebay picture)

If you want to be sure + is plus and - is minus, you have to check Input side of chip + and -, the chip doesn't care, handles both equally.

Pin 4 from top if you hold board equal to ebaypicture is right channel plus (signal) input side, and you should be able to follow that to inputsocket on pcb, pin 5 from top is negative/shield, again chinese don't follow this, and name it left.

On input side of chip 6th pin from bottom should be - negative/shield, 7th pin from bottom is + plus (signal) and should go to input pin on board


I wrote how TI chip connects inputs to outputs according to TI datasheet. If inputs are connected differently in real life on your PCB regarding plus and minus, output plus and minus changes too. Is not very likely, but never know:)

[Poultrygeist]

Poultrygeist, I got the Ten Tec that you mentioned on ebay. Thanks for the tip. Not a bad price.

It is going to power my newly acquired 3118 amp.
http://www.shenzhenaudio.com/smsl-sa-36a-pro-20wpc-tpa3118d2-digital-amplifier-power-adapter.html

With the stock power supply, I thought that the amp is good for the money, but not great. I'm very curious on how the Ten Tec will sound.

I'm running this amp with the volume control turned all the way up, since I've have a prreamp. Is there a possibility that the volume control causes degradation? Can and should it be bypassed? I have not opened the case yet to look inside to see if it is possible.

To my ears the volume control on the red board does not negatively affect the sound. When used with a preamp the knob should be turned all the way up.
I just picked up an Astron on ebay for $36 shipped.

[wushuliu]

Upgraded some of the caps in the Astron and it is a very noticeable step up. The largest cap is a Sprague and I may not replace that as Sprague are supposed to be pretty good I think.

[Markvdv]

Upgraded some of the caps in the Astron and it is a very noticeable step up. The largest cap is a Sprague and I may not replace that as Sprague are supposed to be pretty good I think.

You can look at the date code on the can. Some also regenerate those caps by applying voltages, not sure how it all works. My little smps was never used, I was told the caps might even be worse after being stored unused a few years.

[HaroldHill]

I haven't dated my RS-12A, but I suspect it's similarly old... it would probably benefit from a recap as well, although I'm thinking for convenience I might just buy a brand new unit.

I understand that the first two digits of the serial number are the year of manufacture.

[rhing]

Upgraded some of the caps in the Astron and it is a very noticeable step up. The largest cap is a Sprague and I may not replace that as Sprague are supposed to be pretty good I think.

If it's a large blue Sprague 36D computer-type cap or similar, then it's probably a keeper. I considered one of those, but they were pretty expensive--more than the $38 I spent on the Kemet (Rifa) PEH200 electrolytic cap I installed in my Astron RS-12A.

[Markvdv]

They are not like filmcaps, as I understand it all elco's deteriorate with age, some might be worth the effort to try and regenerate? Expected life for most Spragues is 1000 hours, which is like always at max temperature. Shelf life is the same most of times for new ones, but read few times about applying different voltages in some kind of sequence to bring them back to life, like they did with all the Roedersteins NOS they offer for example.

[rodge827]

Gents,
Can a single Astron/TenTec power supply be used for multiple pieces of gear?
Assuming the amp rating hasn't been overloaded.
As noted dedicated power supplies are the best for sound, but was just wondering.

[wushuliu]

If it's a large blue Sprague 36D computer-type cap or similar, then it's probably a keeper. I considered one of those, but they were pretty expensive--more than the $38 I spent on the Kemet (Rifa) PEH200 electrolytic cap I installed in my Astron RS-12A.

Yep, one of the big blues...

[dboy]

Having got my green Audiobah board hooked up at last I just wanted to note that I am finding the sound significantly better than the blue/black board that I modified. The changes to the blue/black sounded like clear improvements to my ears, but the Audiobah board is preferable even in stock form at the moment. The sound is not particularly clearer, but seems more refined and overall just more 'right' (particularly with voices).

Obviously it is more difficult to modify the board beyond just changing onboard electrolytics and possibly inductors. But (based only on comparison of these two) for anyone reading who is wondering which board they want in order to use stock I would personally suggest 'go green'.

[Markvdv]

Good to hear! On taobao these green audiobah boards are 10% cheaper then red YJ board and 30% cheaper then blueblack YJ board. But source(gainsetting) and speaker(outputfilter inductors) can be part of difference in sound. Output filter inductors audiobah are 22uH, for blueblack 10uH. What is the standard gainsetting for this green board now, I think it was 32dB or even 36dB some months ago, YJ boards standard gain is 26dB I believe.

[dboy]

Mark, thanks for the info on the inductors on Audiobah board - I was just wondering that as I have some other 10uH inductors and was wondering whether to swap 'em. I'm guessing the filter will be compromised if I do...? I'm listening to the board now on speakers with CSS FR125sr (drivers 7ohm nominal) but will be also using the boards with Alpair 7.3 and probably others too.

Gain on Audiobah board is currently 26db according to EBay listing.

[dboy]

I took the plunge and (following Sharpi31 on diyaudio) removed the input caps on my Audiobah board. I then connected (hardwired) the balanced inputs of the TPA3116 to the isolation transformer that is the output stage of my Buffalo II DAC. The DAC has firmware volume control, so as of now between the output pins of the ES9018 chip and the input pins of the TPA3116 there is only some wire and Sowter 3575 transformers wound with OCC copper (10K:10K isolating transformers).

It sounds very nice, considering that I am using a completely stock Audiobah board powered by a 12v adapter that came with a Yamaha keyboard well over a decade go. Bass is not as deep or powerful as I was getting with my TA2020 in a similar setup, but is wonderfully textured and the soundstage is huge. The sound overall is very warm, intimate and yet spacious - as you would expect. It shows enormous promise for when I sort the power supply and other details.

I measured DC offset at the speakers - getting 2.1mV and 0.2mV so that seems fine. No problems with background noise so long as the DAC is on. If I turn the DAC off but leave the amp on then there is a worrying hum coming through. It doesn't seem to cause a problem (so far!) but rattles my nerves a bit. It cannot be a ground loop because there is galvanic isolation, but I have had similar issues before using the isolating transformers in this way. Seems to come with the territory.