I have several.. last bought from NIXIE at RM4.50 each! Now two has been used, one for Junior's T-Amp(buffered), one in my buffer pre-amp.. so far so good!

i do not have volume pot now...since most of the time i control it via the soundcard level.

is it a must to have a physical volume pot for the t amp?

im going to order a bunch of 0.1uF 5% film cap to replace the SMDs

CYL, you sure are unlucky or been extremely critical of JP volume pots. Lai and I also bought ours from RE Spares but there is no problem so far. You already changed the input and power buffer caps? What caps did you opt for? How's the SQ so far?

If you feel the presence of discreet resistors and caps would make your T-amp board look ugly, you could instead opt for better grade SMDs from Vishay or others which are available at Farnell. Bsl is right that changing SMDs to discreet components would dirty up the sound and increase distortion figures. I would not be worried with that myself as that is exactly my aim here. Most critics of T-amp find it too clean-sounding and some of us here do know that absolute accuracy, neutrality and sounding clean could not be equated with musicality and ultimate music enjoyment. Tonal colour is important and should music lovers worry too much about dirty sound and distortion figures, many of them would not have ventured into "valves and vinyl".

I am happy your friend got himself a T-amp too. One more guy converted, who is next?




This post has been edited by Y.C.: Nov 29 2008, 12:47 AM

No physical pot necessary. Your soundcard level control would be sufficient.

Where are you ordering those caps?

either farnell or RS...

now the option is... to replace it with SMD or typical film ones

Now, that is your call!

Initially the pot from Nixie is ok but after sometime, the problem start. I've even tried a little contact cleaner (I thought my environment is very dirty ) but still the same...Like I say before, no need DMM, just bring you along

Again,
It's also 'luck' even with parts from NIXIE!
Even at NIXIE they have 'real' stuffs and 'cheaper' stuffs of the same brand.. use the sentence, 'saya mau original punya!'.

A story.
I bought a relay from NIXIE. Went home tested it, it was great. The following week I went again to get another one bringing in the sample. Now the price is RM2 higher! I asked why, the guy said 'this is original'. WTF? I bought a 'not-ori' last week? Comparing physically the two items to my surprised, the 'not-ori' one looks better with better finish. Since I already bought a 'non-ori' one, I might as well bought another one!

What's intriguing is that both the stuffs sits in the same tray! I asked the guy how he knows which is the ori ones.. he just laugh!
If he messed up, I got the real one at 'non-ori' price!

Not a peace of mind, huh?

Actually the price I'm paying for JP/JL pots is too good to complain but when the pots keep failing, just imagine the frustration...though I'm unlucky with the ports but I'm lucky that I found T-amp

For the caps, I've use the recommended MKT1822 and Panasonic FC 470uF. The SQ, not really run in yet and it is left idle as the L+R channel is not balance now.

For discrete upgrade, can you guys comment more on its sonic improvement? How much different does it make with SMD..Do you like it with discrete? Since its picking up noise, the result would be different for each of us...if it is not to our liking, hard to revert back unless spend another RM55 and time to run in the T-amp again...

cyl100,
There's some postings in V1 with regards to SQ of the SMD replacements( I think). I did it and there's looking back. BTW I am still using the F-ELNA for my input caps. So far they have been good!
Will wait if they're gonna wear out, hope not! I have other caps standing by in position..

i would choose SMD components at the same value and grade with the replacement ones, although is much cheaper, but the soldering skill required for soldering SMD is real KUNG FU...

or maybe in the end i need to get a professional soldering station

Yes, that would be handy!
I mostly use my Hakko Presto and only on some tight positions I had to use my fine tipped made in china CT soldering station. You need steady hands, sharp eye sight and lots of patience!

The difference in SQ of using discreet compos are quite pronounced (we never tried out better SMDs). The 4 pcs of 20K input resistors actually increased overall resolution and clarity of the T-amp further. As for the rests of 0.47uF and 0.1uF caps, Jazzy wrote a review immediately after he completed his stage 1 mods; try finding it in the Ver 1 thread. During our 1st T-amp t/t, I believe most of us who heard actually like SQ of Jazzy’s T-amp with discreet compos, so question of reverting back to SMDs never arise. We didn't hear noises; the discreet compos are slightly more colourful and dirty-sounding just like using a discreet attenuator over carbon volume pot.

Main problem is with desoldering out the SMDs and soldering in the discrete compos. Try to keep the legs as short as possible and use a 15W fine tip Eltax soldering iron. I finally got one myself but as I need to be out of town this weekend, no fiddling with my 3rd T-amp until next week or so.

I would agree with Y.C.
The 20K input resistor replacement make one hell of a difference! and listening is believing!

One warning though.. careful with your desoldering pump! The tracks are so small/thin, if you're not careful, you may suck it out with your pump.. someone suggested a desoldering braid which I think would tremendously helps in this situation. A Pro's Kit solderwick, 2.5mm wide, 1.5 meter long would costs RM3.50 if I am not mistaken.

Y.C, you got a 3rd T-Amp to work on?! Good for you!

This post has been edited by jazzy939: Nov 29 2008, 09:34 AM


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What exactly did you replace it with, different value, no?

using my spare t-amp to practice soldering out SMD, so far so good it takes my clumsy hand 10 sec average to remove each 20K smd resistor...

however to solder in new ones..... might not be that smooth

i was thinking if can use 0.1% metal film resistors? wouldn't it be better?

This post has been edited by Monkey King: Nov 29 2008, 11:25 AM

I use exactly the same what Y.C is using: Vishay BC 1% tolerence metal film resistors.

Monkey King, 0.1% might be an overkill as the temperature rise of the amp is kinda small, so personally I do not expect the resistance to drift so much, so a 1% tolerance would be sufficient.

However do not stop yourself if you wanna use a 0.1%.. it would be interesting to know if it does 'improve' the sound, yes?

well i cant really tell how much it improves since i never tried the 1% yet... anyway...most 1% are quite cheap... 1/4W type would be sufficient eh? hehe

now i have an excuse to use my another t-amp to replace my car amp...

i furbared the car amp when trying to change the op amps... damn 2 layer PCB... too lazy to figure out where is the problem now..declare RIP...

well my question is, direct connect V+ to battery positive (with a fuse of course) and GND directly to ' - ' post of battery.

would this t-amp drain away the battery juice over time via such connection? since the board dosent have place for me to connect REM+

plan to use it to drive dual 6 x 9 at rear

This post has been edited by Monkey King: Nov 29 2008, 12:32 PM

Monkey King,
The amp would drain few milliamps, still why waste when you can put a power switch, right? If your head unit has a REM+, use it then direct or via a relay.

xtorm should be able to answer this as I have not use it in my car, but I don't see any problem the T-Amp driving a pair of dual 6X9 speakers. 4 ohms, right?

well yeah, now i guess i would use a switch for it till i can find a relay circuit for it....