Hi,
I'm new here, Met March05 at Nixie and he introduced me here. I am so glad that I drop by, you guys are a fun lot.

Mrch05,
Take the Sanwa, its great value for money, I have on of those 880 too; Save the money for other instruments like Little ghose suggested.

Cheers

KenC

This post has been edited by KenC: Feb 13 2009, 07:39 PM

Jazzy939,

I only hope I won't inflick more damages...

Show you one of my war scares...


Attached thumbnail(s)

one of my very early DIY Gain Clone using LM1375, end up give to one of my ex-boss as present... to clear space and you know what la...

Use tissue box as chassis with some mod.

the top left is power switch, the middle is volume pot, the right is 4-position input selector switch.

Can see the intestine in the attached pic. You guys like?

Cheers

KenC


Attached thumbnail(s)

Glad that you like it.

Donno the ex-boss like or not leh... boss like to put up square face in any occasions ma; from what I know, he never took it out from his AV system.... donno kedekut or he like...

No need exotic component everywhere one la... I normally choose from what is readily accessible. I find Rubycon caps off the shelf in Malaysia EE hardware stores very good for PS. As in signal circuits, I avoid Electrolitic caps when even I can use any plastic caps will do, my favurite are MPK, but then everone has their own preference for any reasons.

EI trans? you must know their characteristics ma... keep your signal circuits >1.5inch from the trans any you will keep those EMF at bay. if not, implement a faraday's screen loh, easy what. If trans vibrates, return to supllier la! or pur rubber feet to isolate the vibration from the chassis loh, better still put outside.

Only when you do thing like the attached pic then you guarantee all sort of noise and hum problems.... (I did it on purpose just for the challange... )

It is not absolutely true that expensive=better...

BTW, I always make sure the amp has some weight so that can hold the cables connected to the amp and not swivel around when I turn the volume Pots.


Cheers

KenC


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Hi Jazzy,

Its an Aikido preamp, P2P, regulated PS, 6n1p front 5965 back. 4 triodes per channel, P2P on PCB ground plane.

This circuit topology is soo neutral!!! It tames characteristics of tube, most tubes I tried don't have drastic sonic characteristics.

Difficult to build oh....

Attached is much more simple preamp using 1626 during my early stage of learning tubes.


Attached thumbnail(s)

I actually build quite a few of experimental preamps.... easily over 20 sets ... some gave away, most dismantle for more builts... now only have 3 units of Aikido with different construction/layout/gounding techniques...

Phono preamp, MC?

Its very easy to design one.... and there are thusands of circuit freely available if you google a bit.

I wouldn't recommend anyone to build a phono as 1st project, unless
1) they are familiar with high tension electricity
2) they had learnt how to tame hum/noise
3) sure with RIAA
4) buy a kit.

Very easy to
1) get killed
2) discourage.

No pun intended

I would suggest a simple buffer pre-amp for 1st time builder. Interested?

Cheers

KenC

Hi,

Yes, we should start a new thread for a tube buffer pre amp.

BTW, where you guys get the T-amp?

Cheers

KenC

Thanks jazzy, just PM him. wonder if there are higher power units?

Also curious what speakers you guys used for the T-amp?

Jazzy,
Thanks for your reply,

More question,
What is
a) the input Impedance?
b) Input sensitivity?
I am sure the answers are within those ~200pages of threads, I might have to get new glasses after reading all... Can someone help save the reading time?

Cheers

KenC

Thousand thanks!

Zin 120k very high vor... why ppl ask for buffer?

Input Sensitivity 200mV, even can play turn table MC direct (almost...)

Why ah?

Like it or not, either active or passive, a pot will always be there one.

TO be precise, buffer amp is for reducing the source impedance to lower then the input Z of the next stage, normal ss amps has Zin of 20K~50k, 100k, even chin chai make one tube can give output impedance lower then 100k, SS one even lower the 5k olso easy only...

A line amp is to overcome whatever sum of capacitance there is between the source and the power amp.... This one make more sense cos some ppl like to use very long interconnect...

It more convincing to build line amp, at least to tipu ourselves into comfort of dumping more money into it?

BTW, to the train and untrained eye, buffer amp and line amp, looks the same, cost the same, works the same.... mega_shok:

IMHO, line amp and buffer amp are in fact the same thing. different names just to syok sendiri only

This post has been edited by KenC: Feb 16 2009, 10:03 AM

VA is approximation to Watt, easy to find out, 12V x rated current of tranny = VA the bigger the better,
T-amp 1amp cukup makan oledi, 30VA oledi good, 60VA better, 300VA become kow kow, 1kw lagi syok.

Try seal lead acid battery, bigger-is-better applied as well. use only 12V battery, at full charge its 13.8V any bigger you can have goreng T-amp for buka puasa...

Unless you are running class A, PSU must be rated for maximum power when using a regulator, if unregulated, tranny can be slightly smaller at operation power rating.

hope this helps


Ken

---

Added on August 30, 2009, 1:16 pmxtorm,
Film type POT are not balance or accurate at both extreme ends, normally both side also not balance and they are not suppose to mute the amp... its how they work... can not complain one... if want balance, make step attenuators... but they still doesn't mute the amp because they are still potential divider.

Add a mute switch or swith the amp off if you want to mute it.

Cheers

Ken

This post has been edited by KenC: Aug 30 2009, 01:16 PM

300VA or even 30kW transformers won't blow the amp up, any amp "take " power when they nedd eg, transient, big bass etc, the PS punya job is to supply what ever the amp need .. with ease... & forever the tranny will stay cold, this give the relax sound and stable bass... poorly set up won't show such difference. because the blurr sound can covers up severe flaws...

Hope this helps.


Ken