Those caps look suspiciously like the ones I posted in post #314.
I just wonder if the guys in Hong Kong are selling them cheap or are they selling cheap clones ?
Unfortunately I can't be subjective hear (excuse the pun), because I sold it.
I do prefer the more linear (logarithmic) nature of a true pot.
I've read that the "Lightspeed" isn't all its cracked up to be because of audio distortion.
I do prefer true pots for smoothness too, still in a DCB1 I preferred carbon to plastic but it had not good channel matching so a 21 step make before brake SMT cheapo switcher was a good compromise in the end. And cleanest of all sounding.
When they come up with a reasonably priced 40 pole switcher I might try it again. My experience of 23 pole (might be 21) was diasappointing, hence my reason for selling it.
That would be best, 40 pole. There are some relay clickers with many steps kicking around on epay maybe.
I have seen something Chinese kit like with many relays not that expensive, can't remember now exactly. And there is some chip PGA2311U kit with remote and LCD even.
One of the valve threads refer to a site that sells a switched attenuator.
It has a single 6step coarse setting switch in the middle. You can select the relative attenuation of the steps. This is preceded with a pair of 12step fine settings switches either side of the central master switcher. This fine setting can adopt any attenuation per step to fill in the gaps between the coarse settings. Three cheap 12 pole switches giving 71 levels of attenuation and works as an effective fine balance control as well.
Try searching Glassware or Aikido.
Or three very high quality switches and build a copy yourself:
two single pole 12way and one double pole 6way and a selection of good resistors.
It has a single 6step coarse setting switch in the middle. You can select the relative attenuation of the steps. This is preceded with a pair of 12step fine settings switches either side of the central master switcher. This fine setting can adopt any attenuation per step to fill in the gaps between the coarse settings. Three cheap 12 pole switches giving 71 levels of attenuation and works as an effective fine balance control as well.
Try searching Glassware or Aikido.
Or three very high quality switches and build a copy yourself:
two single pole 12way and one double pole 6way and a selection of good resistors.
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Newbie here, with a few questions.
Here's my potential set up:
Cd>P-1A (re-clocker)>P-3A(DAC) (both powered with Monolithic ps)>B1>power amp
Here are some specs for my power amp:
Input impedance R=25K ohms
C=1.0nF
Input sensitivity for 1W/100W out 70mV/700mV
Voltage gain 40x (32db)
Also, the output for the DAC is 2.5 volts, output impedance is 100 ohms, input impedance is 75 ohm.
I guess my question is, where to put the buffer: would I install the buffer after the volume control...?
Thank you,
df
Here's my potential set up:
Cd>P-1A (re-clocker)>P-3A(DAC) (both powered with Monolithic ps)>B1>power amp
Here are some specs for my power amp:
Input impedance R=25K ohms
C=1.0nF
Input sensitivity for 1W/100W out 70mV/700mV
Voltage gain 40x (32db)
Also, the output for the DAC is 2.5 volts, output impedance is 100 ohms, input impedance is 75 ohm.
I guess my question is, where to put the buffer: would I install the buffer after the volume control...?
Thank you,
df
OK. I've cut corners with my B1.
Where do you think the greatest impact will be in improving it.
My Transformer is minimal - only 15VA it does feed a MASSIVE capacitive multiplier and then is regulated. There is NO noise on the B1 at all.
C100/200 are simple WIMA MKS4 1uF
C101/201 are 2 x 4.7uF Metalised Polypropylene Drops of unknown origin (Ebay)
I've ordered some 33uF Mundorf Caps to replace C101 and C102, these are bypassed with 1n5 Polystyrene.
This thing is BLACK AS THE ACE OF SPADES sonically. It is SILENT. The BASS is nice and TIGHT but the MID/HIGH just needs to have a bit of sparkle added to it.
I'm also hoping to get some 1u5 Auricaps to replace C100 and C200.
Where do you think the greatest impact will be in improving it.
My Transformer is minimal - only 15VA it does feed a MASSIVE capacitive multiplier and then is regulated. There is NO noise on the B1 at all.
C100/200 are simple WIMA MKS4 1uF
C101/201 are 2 x 4.7uF Metalised Polypropylene Drops of unknown origin (Ebay)
I've ordered some 33uF Mundorf Caps to replace C101 and C102, these are bypassed with 1n5 Polystyrene.
This thing is BLACK AS THE ACE OF SPADES sonically. It is SILENT. The BASS is nice and TIGHT but the MID/HIGH just needs to have a bit of sparkle added to it.
I'm also hoping to get some 1u5 Auricaps to replace C100 and C200.
Attachments
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The little circuit board at the top right is a mains filter. I took the componnets out of a high-end VCR and just mounted them on a PCB.
The little circuit board in the centre is the LM317 regulator.
The big board on the top right is the capacitive multiplier.
The B1 is obvious.
The little circuit board in the centre is the LM317 regulator.
The big board on the top right is the capacitive multiplier.
The B1 is obvious.
Output cap is greatest opportunity for affecting sound. I would suggest Obbligato Oil as quality inexpensive choice. Get a bigger trafo and drop regulator and build as Nelson designed or try DCB1 for what i believe is an upgrade. The B1 is not really suppose to change or add anything, at least that is the concept.
Signal wiring is all over the chassis, except at the transformer end.
I can't see any small loop area twisted pairs.
15VA transformer, is that also 15Vac? Then 1Aac is plenty.
I can't see any small loop area twisted pairs.
15VA transformer, is that also 15Vac? Then 1Aac is plenty.
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I could go for a 50VA 15 volt traffo and drop the regulator. I can't see how that would improve the top end though.
Exactly the same as the commercial version.
Noise is not an issue. Nor is pick-up.
Twisting pairs together will introduce capacitive loading which is opposite to what we are trying to achieve.
Read a review of the B1 on some of the review sites. I have never heard it described as anything other than transparent. I can assure you it is not limiting your upper end, as it has extremely wideband response. It may be revealing other shortcomings in your signal chain. I suggest building as recommended only because that is the only way to truly judge its performance. Other than doing this, cap and component choice is your only tweak.
The First Watt Model B1 Buffer Preamplifier Operating at the speed limit! Review By Dick Olsher
B1 in front end
6moons audio reviews: Pass Labs INT-150
Perhaps you are realizing that your previous pre was coloring the sound a great deal more than you were aware of.
The First Watt Model B1 Buffer Preamplifier Operating at the speed limit! Review By Dick Olsher
B1 in front end
6moons audio reviews: Pass Labs INT-150
Perhaps you are realizing that your previous pre was coloring the sound a great deal more than you were aware of.
I found that MKP1837 caps as a bypass work well. Also I prefered The B1 with a battery supply compared to both a wall wart or smps and as you say noise was never a problem with the B1.
Currently I use either a TVC or a DCB1 with an LDR volume control both with excellent top to bottom performance.
Currently I use either a TVC or a DCB1 with an LDR volume control both with excellent top to bottom performance.
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I'm driving an Aleph 4 which sounds perfect with nothing in the signal chain..
At the input is an Arcam CD36.. again transparent.
Caps it is then.
Why do some guys recommend massive transformers, and others regulators ?
the B1 only draws 20mA at 18V. Allowing for losses and LEDs lets say 100mA at 18V.
A 15VA transformer is WELL OVERSPEC for a 1.8VA load ?
I think the transformer has more to play at LF. At HF I'm going for the output caps.
At the input is an Arcam CD36.. again transparent.
Caps it is then.
Why do some guys recommend massive transformers, and others regulators ?
the B1 only draws 20mA at 18V. Allowing for losses and LEDs lets say 100mA at 18V.
A 15VA transformer is WELL OVERSPEC for a 1.8VA load ?
I think the transformer has more to play at LF. At HF I'm going for the output caps.
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