B1 Buffer Preamp

B1 Caps

I use NOS Vitamin Q's. Some have sprung for the Mundorf, and others simply move on and build the dc version and don't have to worry about caps anymore.

I have 2 DCB1 boards unbuilt,I don't think I can
do DCB1 because I use DIY Charlize 2 amp
and it has no DC input caps,I am thinking that would be a bad idea
potentially harmful to the amp,I wish I would have drawn that conclusion earlier.
 
You could use a transformer :) Might be pretty expensive though.
I have no DC blocking devices from source to speakers but I know I am taking a risk as someday something will go wrong. In the meantime I will reap the benefits.
I used Clarity Caps in one B1 I built. Was very nice. Also tried PIO from Russia and really liked that to. I think I did the Axon caps, but dont recall that build very well. They were cheap though and that was a plus.

Uriah
 
B1 Caps

I tried the Axon first the did not hold a candle to
Sonicap Gen 1.
I think for all the mods I made when I was really digging
deep into it that was a substantial upgrade was
using 220r Riken at output . that was a revelation for sure.
I am digging back in to fine tune and get all I can out of B1
since I can't use DCB1.


You could use a transformer :) Might be pretty expensive though.
I have no DC blocking devices from source to speakers but I know I am taking a risk as someday something will go wrong. In the meantime I will reap the benefits.
I used Clarity Caps in one B1 I built. Was very nice. Also tried PIO from Russia and really liked that to. I think I did the Axon caps, but dont recall that build very well. They were cheap though and that was a plus.

Uriah
 
Output resistors

I recently added Vishay 2575 220r resistors at the input and the Riken 220r at the output. Works great in my system. Clarity and TONE. The timbre is excellent, not dry and threadbare. Sax sounds like a SAX. Saxy.

I am using a combo of Mundorf and Clarity Cap capacitors. Tempted to try Dynamicaps. I am waiting for my Cary pre to come back from repair and compare to the B1. I may sell it and build another B1 trying the Dynamicap and all Vishay 2575. I would like to be able to switch between Vishay and Riken on the output. The Vishay would sound best on great audiophile recordings and the Riken on the leaner recordings. Hmmmm.....
-Howie
 
The Riken have a much punchier fuller sound at output
than Vishay,I actually did not like Vishay at input or output
after trying many combinations I settled on PRP at input
and Riken at output 330r on both.try it you will be pleasantly suprised
I have been thinking about trying Dynamicap as well.
In post #2948 I misspoke about 220r I used 330r.

I recently added Vishay 2575 220r resistors at the input and the Riken 220r at the output. Works great in my system. Clarity and TONE. The timbre is excellent, not dry and threadbare. Sax sounds like a SAX. Saxy.

I am using a combo of Mundorf and Clarity Cap capacitors. Tempted to try Dynamicaps. I am waiting for my Cary pre to come back from repair and compare to the B1. I may sell it and build another B1 trying the Dynamicap and all Vishay 2575. I would like to be able to switch between Vishay and Riken on the output. The Vishay would sound best on great audiophile recordings and the Riken on the leaner recordings. Hmmmm.....
-Howie
 
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Thanks for the input. I'll check into the PRP resistors. I read in this thread or another about the Riken and Vishay, so I tried them. I only bought 2 Vishay due to the price. I guess just testing parts in the circuit will give me experience so I can choose wisely. It is a time consuming process. I am new at this DIY, but am finding it quite interesting and rewarding.

Are there sockets that I can solder into the board that will let me plug in resistors without soldering them so I can swap and listen? I'll look into that.

Many thanks to Nelson Pass for giving us a simple and remarkable sounding design. I intend to find a 'definitive' parts mix that will make the B1 the best it can be in my system. Following the resistor change I have noticed greater sonic change between the 24v wall wart and the Ryobi 19.2 volt battery for power. I have much more to learn.
-Howie
 
You can try it, but there are three problems that I can see.

1.) the 1:3 turns ratio will give a 1:9 impedance ratio.
The receiver will see 9times the B1 output impedance. 9k instead of 1k
The B1 will see one ninth (1/9) of Rin of the receiver.

2.) Normally Audio transformers are manufactured to suit a very narrow range of load impedance.

3.) The B1 has a current output that suits loadings down to ~5k. The transformer may not be able to drive much current (only 1/3) is available.
 
input selector and digital pot

Ive search this thread to find a clue to use the B1 together with a Input selector and Dig. pot. I'm in the process of building the F5 and wonder if I should use the B1 or can use the BZLS which now plays in combination with Aleph 30.

with the BZLS I use this input selector/dig pot. from Lite Audio. the Z-inp. is 47.5K.


My question is Can I use the Selector in front of the B1?
 

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Hi Wijgers,

I own the same Dig pot, I used it with success for a past project and recently swapped for the R2R discrete one, same manufacturer, it uses same remote control and display unit but instead of the CS3310 chip it is made with a resistor ladder. I am running into some issues for the implementing, as the card of the R2R has two grounds, one for IN, one for OUT, I wonder which one to connect to CCW on the B1 board? or maybe rather connect both + the CCW to the star ground?
Another option is to put the Buffer after the Dig pot just using it as pure buffer, but then what about the impedance match? Maybe would it be preferable to solder a 100k resistor instead of 25k as a pot on the B1 board?
Many questions..
 
there is a way...

Hi,

I'm not sure if this is what you are looking for but "6L6" on here showed me a way to modify the B1 to allow the use of a selector switch, as opposed to the toggle switch it calls for.

I don't know how to post photos but if you write me directly at ms_williams@hotmail.com I would be happy to pass on the diagram that Jim so kindly provided to me.

Works great! He really saved me a lot of head-scratching frustration! :confused:

Mark
 
In France we say, "never have too much of the good things". I think I will just do that...apologize do be greedy!

Jim, how would you connect the grounds of the B1 and its PSU to the star ground?
I have a Digital pot with two grounds, In/Out, with its own PSU and I have no idea how to wire all this people together..

Your help is highly appreciated!

Cheers

Laurent
 

6L6

Moderator
Joined 2010
Paid Member
There is no 'correct' way to ground a circuit like this, but I would try this -

Connect the Regulated PSU to the B1 board via 2 wires, + and - Begin by not connecting the buffer to earth, except through this connection.

Connect the PSU to safety earth near the negative pole of the capacitor closest to the transformer.

Connect the Mains earth to the chassis to make safety earth. Use a star washer to ensure a good connection to the metal.

Use isolating washers on the Input and output RCA jacks. Do not let them touch the chassis.


Do you have any information or a link to the attenuator you are using?