Building a symmetrical psu B1 buffer

[sutantoroy]

Excuse me....

Are Allen Bradley (AB) resistors suitable to be used in this buffer? Which path is more suitable to use this AB resistors? I heard that this resistor is tend to drift up the resistance value due age and high voltage, but adding more enjoyable sound colouring.

Referred to post #75, recomended the 220R to be a good quality resistor. What is good quality resistor? I have AB, Rhoderstein, Dale, unknown carbon film, and unknown metal film for this value. Which one is recomended? Why this value is recomended to use good quality resistor while the others not?

Thanks

[AndrewT]

Originally Posted by sutantoroy

Why this value is recomended to use good quality resistor while the others not?

Hi,
a bad resistor is one that
changes value with temperature.
or
changes value with voltage
or
changes value with time
or
changes value with humidity
or
changes values with mechanical strain
or
has a value that does not match what it says on the tin.
or
a few others that I have not remembered.

Reducing all of these variations moves one closer to a good resistor.
One can never eliminate all of these variations, no matter how much money one is prepared to pour into the pot.

[sutantoroy]

So the point is to meet the closest value based on the schematic?

Phew...that was close to me using bad resistor

So, it would be better to find a 0,1% tolerance within schematic value. The answer is Roederstein right? I already have it, just not sure which one should be use?

Thanks for the answer

[AndrewT]

0.1% only satisfies the tolerance requirement (what it says on the tin).
You have ignored the other 5 requirements.

This value may be the spec that has widest tolerance to small changes in the circuit being considered.
5% might be good enough.

[Salas]

Originally Posted by sutantoroy

Excuse me....

Are Allen Bradley (AB) resistors suitable to be used in this buffer? Which path is more suitable to use this AB resistors? I heard that this resistor is tend to drift up the resistance value due age and high voltage, but adding more enjoyable sound colouring.

Referred to post #75, recomended the 220R to be a good quality resistor. What is good quality resistor? I have AB, Rhoderstein, Dale, unknown carbon film, and unknown metal film for this value. Which one is recomended? Why this value is recomended to use good quality resistor while the others not?

Thanks

The 220R are gate stoppers and output dampers for capacitive interactions. The ABs are good for stoppers because carbon. The absolute value determines nothing critical in this circuit, as long as it is roughly 220R. Your best sound is Shinkoh though, if you have access. The resistors here are for terminating the pot, the inputs etc. Not critical for accuracy, but you will listen to them in such a minimal circuit. Chose by ear in your system. Don't change the recommended values, but near as 215R is OK.

[sutantoroy]

I see...

The 220R (gate stoppers and output damper) are giving the significant differences using difference resistor. Okay, I'm gonna try it myself to choose which one is suite on me.

I myself still curious about the 'magic' of resistor, hope I would aware the differences. But if I can't, still ok, not a big deal.

A little share here,
I made regulated power supply B1 buffer before, and compare it with this symmetrical shunt regulated. Then I was awesomed by the performance of this symmetrical buffer. It has more dynamic at low and detail at high. The regulated PS buffer has more thick mid, but for the total hearing i prefer the symmetrical.

For the info, the symmetrical using relatively cheaper components (you know crt, he is the type who dont like 'expensive things' ). But for the tonal quality I actually prefer the regulated power supply B1 buffer because i hear the sound is more live (I dunno what it say, just more like hearing the real things supposed to sound)

The Conclusion is, this symmetrical should be a better than the previous I made.

Thanks

[Salas]

The subjective realm is quick sand. Each one to his own preferences or prejudices. Try and see.

What you made exactly for symmetric psus? My stuff P2P? Photos? Those crt posted? You are his friend? Experiment with resistor quality in the audio part, and pot quality. You will find the tone you like and you will retain/expand its slam and detail over the regular. Depends much on your rest of system and on what you think is ''real'' for sound. But if you hear more information, its tell tale that a circuit is the more suitable to choose and tune for tone, as a rule of thumb.

P.S. ''I made regulated power supply B1 buffer before'' you mean the normal B1 with input & output capacitors?

[sutantoroy]

Yes, the symmetric is the one crt make and post in front page

We live in the same town, and actually he is the one who poison's me with these audio stuffs I dont really know about electronic's, but it seem's cheaper to build than to buy, thats why I choose to DIY the stuff.

Yup, the previous i made is the normal with couple caps and LM317 regulated PS.

[Salas]

You are in DIYA so I congratulate your approach.

Just tune your DCB1 with symmetric shunt regs. You will find your best tone for sure. Try all your available audio buzz resistors and pots in its audio part.

[sutantoroy]

Thanks Salas,

I'll post it once it's finished. Although i dont really know about gate stoppers and output damper, etc, I'm gonna learn it (read some basic electronic literatures) while doing the DIY.