Passive preamp

Best impedance mach for Nelson pass B1 what should be the best value for the power amplifier ????? so we will get maximum detail from the source.
 
Best impedance mach for Nelson pass B1 what should be the best value for the power amplifier ????? so we will get maximum detail from the source.

The B1 doesnt have impedance issues with most power amps. It still does need a high gain power amp though.

Any specific budget in mind for the power amp?
 
Having always used integrated amps, I'm a novice at pre-amps. I know that, given my box's buffered and pure-passive outputs:

--- I subjectively prefer the buffered output for the ifi iCAN headphone amp

--- The pure-passive is fine for the M-Audio AV-40 powered speakers. An entry-level speaker anyway.

There are two outputs, I need to output to two things: it works for me... but...

If you do not have impedance matching issues

How would I know? What are the symptoms of impedance mismatch?

jai1611 said:
Passives are VERY system dependent

If the pre achieves the aim of transparency, shouldn't that make it system independent? Or is it this impedance thing again?

~
 
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The B1 doesnt have impedance issues with most power amps. It still does need a high gain power amp though.

Any specific budget in mind for the power amp?

No budget yet just need to know the gain speck then search for good one
 
What I was observed that In creek A 50ir Integrated amplifier.The sound is very details and beautiful and the pre is passive.When I was used same creek passive pre-out with NAD 303 power amplifier the sound was totally dead nothing in it.But when it comes with integrated sounds awesome.

I have heard same with exposure 2010 first edition it have passive preamplifier it sound very good also we connected its pre out with bryston power amplifier its sound very attractive than integrated.So what I think is the exact matching between pre & power even if it is integrated too....
 
What I was observed that In creek A 50ir Integrated amplifier.The sound is very details and beautiful and the pre is passive.When I was used same creek passive pre-out with NAD 303 power amplifier the sound was totally dead nothing in it.But when it comes with integrated sounds awesome.

I have heard same with exposure 2010 first edition it have passive preamplifier it sound very good also we connected its pre out with bryston power amplifier its sound very attractive than integrated.So what I think is the exact matching between pre & power even if it is integrated too....

I am in the same league..I am getting Pass B1 for testing my system in Pune.
If it does not work, then would go for IFI-Itube Preamp. If you live nearby Pune, the you can check the same on my system.

cheers
dheeraj
 
I am in the same league..I am getting Pass B1 for testing my system in Pune.
If it does not work, then would go for IFI-Itube Preamp. If you live nearby Pune, the you can check the same on my system.

cheers
dheeraj


Great to hear you are testing with Pass B1 let me know the result from your side
 
How nelson pass B1 on the highs it will be good on low and vocal what about higts is it good
 
How nelson pass B1 on the highs it will be good on low and vocal what about higts is it good

B1 is very transparent and does not constrict any part of the audio frequency.

It is strongly advisable to perform the simple resistor modification described elsewhere on the B1 build thread on this forum.

In my experience, it has rock solid bass, rich mids and very well extended and liquid treble.
 
B1 is very transparent and does not constrict any part of the audio frequency.

It is strongly advisable to perform the simple resistor modification described elsewhere on the B1 build thread on this forum.

In my experience, it has rock solid bass, rich mids and very well extended and liquid treble.

+1, cant agree more.

The B1 has super clean highs and is extremely transparent across the frequency range!

The first word that comes to my mind for B1 is transparency.
IMHO, if there is one piece of gear you don't want to miss auditioning before making a decision it is THIS!

Also with simple mods the sounds can be further tweaked as an added bonus.
 
What I was observed that In creek A 50ir Integrated amplifier.The sound is very details and beautiful and the pre is passive.When I was used same creek passive pre-out with NAD 303 power amplifier the sound was totally dead nothing in it.But when it comes with integrated sounds awesome.

I have heard same with exposure 2010 first edition it have passive preamplifier it sound very good also we connected its pre out with bryston power amplifier its sound very attractive than integrated.So what I think is the exact matching between pre & power even if it is integrated too....

This is exactly what i am experiencing . Anything with the passive pre is good , also i think it depends on the speaker/source . In a comparision with the 3010S2 the 2010S2 with the passive pre was better . Also in the recent weeks , we tried different power amplifiers with the passive pre ( or ) directly connecting the DAC with volume control , which is better compared to some of type of active pres we tried.
 
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Originally Posted by hifiramr View Post
What I was observed that In creek A 50ir Integrated amplifier.The sound is very details and beautiful and the pre is passive.When I was used same creek passive pre-out with NAD 303 power amplifier the sound was totally dead nothing in it.But when it comes with integrated sounds awesome.


Remember that if you are using the Passive Pre Amp section of one Integrated ( say Creek) to feed another Power Amp (eg NAD) there will be an extra pair of interconnects, with their Cable Capacitance.

If impedances are not matched ( as will be typical for a passive pre) High Freq loss will be the First casualty :eek:
 
Remember that if you are using the Passive Pre Amp section of one Integrated ( say Creek) to feed another Power Amp (eg NAD) there will be an extra pair of interconnects, with their Cable Capacitance.

If impedances are not matched ( as will be typical for a passive pre) High Freq loss will be the First casualty :eek:

But I dont think an interconnect makes that much difference used several brands including VDH only slight change accordingly.But the impedance matching is the magic nothing else.
 
If a pasive pre and power amp are inside the same chasis, the internal interconnect length is neglible. Hence its capacitance is also negligible.

No so for external interconnects.... some of which have a Large capacitance per foot / meter.
Ideal "Matching" would be to have the Power Amp Input Impedance 10 Times that of the Pre Output Impedance.

This is a Tall order for a passive pre.

Often Power Amp Input Impedance is only 2 Times that of the Pre Output Impedance.

The situation is tolerable if there is no cable capacitance to further spoil the response.

Hence what sounds good with internal wiring can sound poor with external wiring...
 
My TLC-1...

Input Impedance: approx 13 kohm
Bufferred output impedance: 250 ohm
Passive output impedance: varies with volume settings, drops as volume increases, 0 at max volume.
When using the PASSIVE output, be certain that the total cable capacitance of the cables is less than 1000 picofarads per channel

Hmmm... well, I always enjoy a visit to the Blue Jeans site :). LC-1 Design notes.

Electrical Characteristics:
Capacitance, conductor to shield: 12.2 pF/ft
Resistance, center conductor: 34 ohms/1000 feet
Resistance, shield: 1.7 ohms/1000 feet

So, over a 1m cable I have approx 33.6 pF. So that's good by >900pF.

M-Audio AV-40
Input Impedance: 10 k ? unbalanced, 20 k ? balanced

Hmmm... the TLC-1 passive output is stated to be zero at full volume, but we do not know what it is at considerably lower volumes. I set the av-40 volume at 3.00, and then the pre-amp comes to between 9 and 12.

(And if anyone is cringing at the combination of a piece of classic kit to AV-40s, sure... but we all have to start the upgrade path somewhere :lol:)
 
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