hi Y.C.,
When you said your LED went dead, dead as in fused/burn out?
1K should more than sufficient(based on calculation)

Bro March,
Will you be bringing your 'goodies'?

I think plan wise is that the start time is at 3pm.. dunno about the agenda.. will take it as it goes..

You're always welcome JC. With or without the boomtubes

Y.C.,
I have a feeling that 1K is too low, so I took a look at my LED, a clear blue which should be having the same current requirements with WHITE LED (I have tested).
I am using a 10K resistor, 1/4W (brown,black,orange) as the current limiter. It's a balance between dim and too bright as I do not want it to be a glaring distraction at night
I believe it should work in your set up too, plus minus a few K if you wish to adjust the brightness... Hope this helps in time for tomorrow's session!

Y.C.,
Not at all. I have a few spares LEDs(blue, white, orange too) and several values of current limiting resistors. If you need any, just give me a 'holler'

Yes those blue LEDs are kinda expensive.. the cheapest I got was RM1.30
Why 10K? Good question! I blew 2 LEDs before I got it right.. Learning the hard way..

I am definitely coming..

Once or twice I do suffer too with regards to 'quality' issues.. that's why I sometimes buy stuffs from JP more than one in quantity eventhough I need only one.. just incase JP= Jamban Products..

Y.C.,
You're most welcome. Get extra for 'spares' just in case..
Yes.. Will bring my 100K passive. It's a 10K actually but a quick swap with a 100K pot is no big deal..

Friday night.. too quiet lah!

Calculation wise, there's nothing wrong with it.. putting it to work.. well we know the story Sorry Y.C. If only I knew the answers...

Y.C.,
Yes I know. I actually measured the voltage across the LED, which reads 2.8VDC! Which means that the current limiting/voltage drop resistor is CORRECT!
Why doesn't the formula reflect this?
In my setup, using the formula; with 13.4VDC supply voltage and 2.8V LED forward voltage, the LED forward current is 1mA! Maybe 20 or 30mA LED current is not the correct figure?

I think we may have missed something.. I have been doing some reading, found something but not conclusive.. needs further 'digging'..
Anyway, just completed re-assembling a 100K 'passive' preamp.. finished testing and it sounded 'not bad' I'd say!
14 hours to go!

I guess this is the price you pay for 'cheap' things... although they are really not that cheap!

I use my variable voltage PSU and a bunch of resistors to get the required/correct current limiting resistors..

Again, a 1mA forward current for my blue LED? Heck, as long as it works..

That would be the only logical answer to your(our) LEDs issues.
1K would be more than suffice.. 470 Ohm being the 'normal' series resistor.
Having that in mind, what about other semiconductors that we bought from JP? Transistors, ICs what nots..?

Great! few hours to go.. I'll be bringing in my Junior..

Catch you guys later.

Easy for you to say!
Yes. I have more than once bought a few 'look like the real thing'.. for obvious reasons they don't last that long.. or circuits don't actually work like they're supposed to..
If it's way too 'cheap' then, it's a sign...

Would it be safe then, to get 'everything' from Farnell or RS?

Have a great weekend bsl.. yes we know, you're gonna be busy...

Good report Bro March.
Thanks for the usage of your superb HB2 and the stands..
Too bad you missed one of the best 'mee goreng mamak' in SJ
Yes. Many thanks to Y.C for the venue, drinks n 'makan' and hospitality..
Good news is, 'someone' already agreeable to use his place for the next T-Amp TT-Session!

Waiting for Y.C to say something..

This post has been edited by jazzy939: Oct 26 2008, 01:34 PM

Never had such a problem. Are you sure it is not originated from your source?

Hi folks!
I was out still celebrating raya.. just got back though..
Yes I did took a photo (one) and here it is, the set-up of the equipments.. Should have taken more but.. we were so engrossed with the music and all, 3 hours (like bro March was saying)seems like minutes.. too short eh folks?

wui,
No progress yet on my pre-amp.. waiting for 'something'
We all know that the stock T-Amp is a little bit bass shy.. by changing the input caps and a voltage increase from the usual 12VDC should improve, however it is quite speaker dependant also! The best bass ever I got was from the EPCOS's 10uF input caps.. mysghooi however is currently holding the record of 22.2uF!

junchoon,
I could make your 'RCA jack' converter in no time As a token of appreciation for offering another TT Session at your place tomorrow! Say, how many of us is taking up the offer? My schedule is clear for tomorrow.. only I have NOT done the LP transfers.. (no phono pre-amp for T-Amp, have to get my Technics wired up.. )
The built in sub on your boombox can be disabled as required with some 'minor' mod. bro March's idea is also very 'interesting' and viable too.. I have to peek inside your 'Virgin's boomtube' ler..

As from me.. our first T-Amp TT Session was a great success!
We can now see how a 'tiny' little amp can be tuned and drive speakers like HB2 with great ease and how musical it was.. even with tunes that we are not familiar with, we were soon flowing with the beat.. someone mentioned Krell?

Lai's T-Amp with the ERO's input caps and the Pana power caps.. I would totally agree! The female voices was really seductive Quite a well balanced set-up and like Y.C. was saying, it would be a challenge for any current commercial setup to beat such a great combination!
Syrupy eh Y.C? I can imagine how Ms. Krall voice would be! Would be mesmerizing! I might reconsider putting back and re-evaluate the EROs again

Not forgetting the great lil' Q-Acoustics which was (to me) excellent with the mids and highs.. if partnered/complimented with a proper sub, a full range speaker system would already in place!

Well.. are we ON or OFF for tomorrow's session? Too soon, no?

This post has been edited by jazzy939: Oct 26 2008, 11:32 PM


Attached thumbnail(s)

wui,
Here it is.. quite simple the circuit is..

The components are:

R1: 270R
R2: Carbon preset potentiometer
C1: 100nF
C2: 1uF tantalum
LM317T Voltage regulator
Heatsink
PCB board

ongbs,
This was intentionally done to make you salivate..

Handsome faces? I do not want to risk corrupting my memory card!

Honestly I should have taken the 'group' photo.. like I said, we were fully occupied.. next time maybe..

Sorry to disappoint you...

This post has been edited by jazzy939: Oct 27 2008, 01:03 AM

Hey! I am no 'geek'!

bro xtorm can't come due to personal/family commitments.
sorry la ongbs, did not take any..

wui,
There's always more than one variations to a basic circuit.
The second link, is using a 22000uF cap.. good luck in getting those.. but you can actually settle for less value caps... hehe

Good work in getting the 13.44 volts! It is more than sufficient to juice up the output especially the bass...!

CDP? I think junchoon have a decent CDP.. more like a multi-disc CDP!
Just bring whatever things that you want to.. surely junchoon have enough 'rooms' to accommodate..

This post has been edited by jazzy939: Oct 27 2008, 07:40 AM