Building a symmetrical PSU B1 buffer

There's a contradiction in what you want - $30 won't buy you the highest fi you can get. However if you want best bang for buck in the $30 range then the 23 step one from eBay seller vintage audio lab is very good value.

I too bought one of those mentioned in the last post but don't have it yet to say anything about it - but it doesn't look as substantial as the vintage audio ones.


Btw his wbt style rca connectors are very good - indistinguishable to eichmann copper bullets in listening tests.


Fran
 
Hi Mr. Salas

I just changed these resistors 30 minutes ago :
Before
1M 1/4W--> metal film (supposed Dale)
215 1/2W--> metal film (my friend told me it is Riken)
20K 3W(I dont use pot, so i change the value of 220K into 20K) --> carbon composite (I dont know the brand, it is brown 3W resistor with 10% tolerance so I guess it is a carbon composite resistor)

After
950K 3W--> AB
215 1/4W--> AB
19,75K 1/2W--> AB

The Impressions:
Before
The sounds quite thick, the high is good, snappy while not the bright one. Vocal is focused. Bass??? I duno, because my speaker isn't bass typical and i am not a basshead, but overall it still good.

After
The sound is quite thick but in a bright sound :(. Vocal is wider than before.

I hope that this is just because I use old stock resistors which arent burn in yet. What is the characteristic AB resistor? For the 470 resistors i use Dale R60 resistors, what is the difference using carbon film in this posisition?

Thanks,

Roy
 
diyAudio Chief Moderator
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Too dependent of your system and taste, too needy of a real examination so I can grasp it and help. What is ''thick'' to you for instance? My general idea would be. A. Review things like clean contacts, the well being of the rest equipment. B. Wait a little to see if something changes. C. Change some more makes.
 
Roy,
Keep trying. You are going to learn something here, no doubt. You are keeping track of your resistor changes and the sonic changes, so for sure you will end up with a sound that is better to your ears than what you started with if you keep tweaking it.
Get some IC sockets like Mouser Part Number 310-43-164-41-001000. Then you can fit different resistors in and out easily without soldering over and over. Soldering to many times will heat up nearby components to much and also will lift pads and traces which will make things really frustrating.
Uriah
 
"Thick" in my previous statement means sound is straight and clear, example: the sound of cymbal. In my relatively cheap PC computer speaker the cymbal sounds can't as clear as my DIY sound system, even for the relatively same loudness level (I am not measuring using instruments, just based on my ordinary hearing adjust the loudness level). The same also on mid/vocal.

For your general solutions:
A --> I'd checked the contact, everything is clean and OK, the rest equiepment should also ok, since i'm not touching other than the buffer itself.
B --> after 2 hours of hearing my ears are getting to adapt the sounds (or the sound were changing :D, duno which one is occured). I feel hearing sounds which someone often call it, maybe, say it as "warm sound", not bright (uncomforting ears) . Hearing Kirk Whalum saxophone seems different than the usual one, different taste. I cant say which one is better, but personally i prefer my old buffer sound. I will wait for some periode to enjoy the changes ;)(maybe there would be more changes after several more times hahhaha)
C --> Do you mean make a new buffer? hm...maybe i would, because it has different taste afterall. :)

@udailey: yeah...I will try another resistors too, feel curious on them. But duno when because the good branded resistors price are quite expensive in Indonesia.
 
diyAudio Chief Moderator
Joined 2002
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C. Of course not. I meant tasting some resistors in the audio part after accommodated enough to each type and brand. For metal, Dale RN55/60, PRP, are typically the reference point for not exotically priced, but special enough.
For carbon, Riken & Kiwame. For Tantalum, Shinkoh and Audio Note. If time passes and you feel that your best tone was with metal, fitting the Dale RN series (light brown, non magnetic ends & legs) or the red PRP can't get you wrong.
 
The last few days I did some critical listening to my symetric B1 with LDR's.
I have setup my build, so it has two outputs, one through B1 and one only with LDR's . Power amps were PD gainclones biamping my Sonus Faber Electa Amator 2 speakers. Input impendance around 11k.
Overall, I preferred the sound with the B1. Bass was better and music had more drive. But upper in the spectrum, especially with female voices there was some sibilance which was not there when I had the LDR alone. Resistors used are carbon generic, really nothing special. I already ordered some Takmans to replace them. Wait and see what happens!
 

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Nice build Vgeorge.

RE the sibilance - just don nothing for a week at least. As Uriah has mentioned previously, there definitely is a burn in period with this preamp and given a week or so, it may go away naturally.

Fran

I will leave the pre playing for some more time and report if I hear any changes.
Anyway, I ordered some resistors already.