Pass B1

[kroyin]

Oops.. atlast i thought to have an shootout of Music hall 25.2 integrated player Pre-out against Pass B1 pre... How it performed.. Not to disappoint ...$600 Music hall 25.2 won.. However for the Price and the music output nothing in this price factor can beat the B1
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That's interesting, I guess the B1 was sold @ $1000,
so I'll look at a 600$ preamp beating a 1000$ :-D

 

[captrajesh]

Oops.. atlast i thought to have an shootout of Music hall 25.2 integrated player Pre-out against Pass B1 pre... How it performed.. Not to disappoint ...$600 Music hall 25.2 won.. However for the Price and the music output nothing in this price factor can beat the B1

Things can't be so simple. Synergy matters much more than costing. I had paired my Class D Audio CDA254 with B1 that I made as well as Murali_n's SSP paired with Cadence Arist speakers. It is no contest, SSP won comprehensively.

 

[srinisundar]

Things can't be so simple. Synergy matters much more than costing. I had paired my Class D Audio CDA254 with B1 that I made as well as Murali_n's SSP paired with Cadence Arist speakers. It is no contest, SSP won comprehensively.

We will test it fully after assembled... I believe in bits and pieces it is having problem.. Hope you will complete the assembly and we will test it against yours B1 against my B1.

Regards

 

[omishra]

We will test it fully after assembled... I believe in bits and pieces it is having problem.. Hope you will complete the assembly and we will test it against yours B1 against my B1.

Regards

Your PS using EI transformer which is not same as r-core performance. Noise floor are different for both transformer operated preamps.

 

[omishra]

Oops.. atlast i thought to have an shootout of Music hall 25.2 integrated player Pre-out against Pass B1 pre... How it performed.. Not to disappoint ...$600 Music hall 25.2 won.. However for the Price and the music output nothing in this price factor can beat the B1
-------------------------------------------------------------

That's interesting, I guess the B1 was sold @ $1000,
so I'll look at a 600$ preamp beating a 1000$ :-D

This is not a technical test, may be for some transperancy matters and for some musicality matters. B1 is my best preamp I have so far and in recet Pune hifi meet everybody witnessed that.

 

[srinisundar]

Your PS using EI transformer which is not same as r-core performance. Noise floor are different for both transformer operated preamps.

Not much know about transformers, digged from net after you indicated.

There are many factors to consider.
Toroids are more efficient.
E-I have narrower bandwidth (a good thing, as it helps prevent noise from the mains entering).
Toroids are smaller, especially in height, and lighter.
Toroids have problems with high inrush current. They may need special soft-start circuitry for the big ones to avoid blowing fuses.
E-I are cheaper.
Toroids look like doughnuts. Mmmmm, doughnuts..

 

[jls001]

Got the B1 kit from Sachin yesterday. He is fast in sending stuff! Thanks, Sachin.

Will try to rig it up over the weekend. And may be even complete the SSPA which is still sitting in the packaging.

Also got:
1) OPS (my second board - will figire out what to do with this one - this one comes with most required parts except R-Core xmer)
2) Source Selector kit
3) and last, but not the least, a quad of LM49990 opamps with the adaptors to be tried on the Hypnotoad MC phono preamp and the CNC MM phono preamp.

 

[omishra]

Not much know about transformers, digged from net after you indicated.

You forgot one important point. Capacitive coupling of mains noise from primary to secondary. That way polluted ground introduces artifacts into analog circuits. Which are amplified to some sense. I experienced even 5-10mV ground noise also makes audible difference to power amplifier output. Forget higher SMPS noises present in Mains.

 

[Santy]

Just completed the PS board. Felt nostalgic.

After 10 years, picked up the soldering iron in hand.
The last time I did was for my own design of a control circuit, for our final year Engineering project (which was an automatic dosa making machine! )

 

[Santy]

Completed all boards.

 

[omishra]

^^ Santy, don't forget that jumper near that 22-0-22 pin on power supply board.

BTW, nice looking work.

For all Pune guys - you can pickup you trafos from me. They are here. I will be sending remaining out station r-cores from Monday.

 

[Santy]

^^ Santy, don't forget that jumper near that 22-0-22 pin on power supply board.

BTW, nice looking work.

[/B]

Thanks Om I will short those points.

I have some quick queries.

1. The PCB is double sided I guess but I have soldered only on the backside except for the 1ohm resistor. So should I do it on the top side on all resistor and JFET joints? Won't the heat loosen the joint below?

2. Where can I find the circuit diagram for the connections between the source selector and Pass b1 and the rotary switch and the inputs sockets?

3. How to connect the Pot to the B1 board? There are no labels on the stereo pot. I guess W is centre point, how to wire the other points.

4. LED on B1 is meant for what?

5. Do you suggest single stranded wire for all interconnecting wires or multi stranded? Any specifications? AWG / Copper/ Aluminium?

6. Assuming the source selector goes into the L/R 1 IN of B1, which one should I 'short' on the PCB's input switch section, L1, R1 to middle or L2, R2 to middle?

Sorry for lot of questions, I think I will have even more. But I guess it may also help other DIY newbies if any.

 

[omishra]

1. The PCB is double sided I guess but I have soldered only on the backside except for the 1ohm resistor. So should I do it on the top side on all resistor and JFET joints? Won't the heat loosen the joint below?

Not needed, but you can do it from upside again, anyway PTH PCB okay from soldering anyone side unless hole gets damaged in rework.

2. Where can I find the circuit diagram for the connections between the source selector and Pass b1 and the rotary switch and the inputs sockets?

I think I have have posted it somewhere few pages back. Pease look behind. If I get the kit handy I will do it.

3. How to connect the Pot to the B1 board? There are no labels on the stereo pot. I guess W is centre point, how to wire the other points.

About pins -
Hold shaft towards you and pins upwards. Two rows of three pins each. Each row is for one channel.
Now for each channel, pins at your left hand side are 'CW' middle are 'W' and right hand side are 'CCW'

4. LED on B1 is meant for what?

That's for discharging one of the main cap which is at 1/2 of the PS rail. Also it's an indicator for PS.

5. Do you suggest single stranded wire for all interconnecting wires or multi stranded? Any specifications? AWG / Copper/ Aluminium?

IMO silver coated copper with stranded wire, anything above #24 SWG will do. If you are not using shielded metal cab then use shielded wire with ground terminated at PCB. Otherwise in closed metal cab use non shielded wire.

6. Assuming the source selector goes into the L/R 1 IN of B1, which one should I 'short' on the PCB's input switch section, L1, R1 to middle or L2, R2 to middle?

'short' on the PCB's input switch section, L1, R1 to middle.

 

[Santy]

Thanks Om for the quick lesson!

2. Where can I find the circuit diagram for the connections between the source selector and Pass b1 and the rotary switch and the inputs sockets?

I think I have have posted it somewhere few pages back. Pease look behind. If I get the kit handy I will do it.

Yes, I am browsing. Now on 7th December 2011 of this thread. I am sure I will find it.
But I asked, assuming that someone would have this illustration on their desktop

 

[TheCoolestOne]

'short' on the PCB's input switch section, L1, R1 to middle.

Om I am a bit confused about this.

(1) Do you mean to say that we solder the source selector wires to holes marked L1 and R1 and then again short L1/R1 to Center?

(2) If so, then L2 and R2 are not to be touched at all?

 

[Santy]

Om I am a bit confused about this.

(1) Do you mean to say that we solder the source selector wires to holes marked L1 and R1 and then again short L1/R1 to Center?

(2) If so, then L2 and R2 are not to be touched at all?

No, output from source selector will go in top left of the P1, labelled LEFT IN 1 and RIGHT IN 1. While in the bottom middle, labelled INPUT SWITCH, we will short L1 and R1 to the middle points below them.

 

[TheCoolestOne]

No, output from source selector will go in top left of the P1, labelled LEFT IN 1 and RIGHT IN 1. While in the bottom middle, labelled INPUT SWITCH, we will short L1 and R1 to the middle points below them.

Thanks for the clarification Santy. I was confused about this.

What about:

(1) Left IN 2 and Right IN 2
(2) L2 and R2 in Inut Switch next to CW below

 

[Santy]

Thanks for the clarification Santy. I was confused about this.

What about:

(1) Left IN 2 and Right IN 2
(2) L2 and R2 in Inut Switch next to CW below

I guess they will remain unused since we are using separate input switch.

Sent from my GT-I9001 using Tapatalk 2

 

[TheCoolestOne]

I guess they will remain unused since we are using separate input switch.

Sent from my GT-I9001 using Tapatalk 2

I meant we dont have to short them do we?

I guess in the earlier builds they were used fr the DPDT switches.

 

[omishra]

Om I am a bit confused about this.

(1) Do you mean to say that we solder the source selector wires to holes marked L1 and R1 and then again short L1/R1 to Center?

(2) If so, then L2 and R2 are not to be touched at all?

That question was related to toggle switch position on pass B1 board.