B1 preamp build thread

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AndrewT

R.I.P.
Joined 2004
plastic film are good. Even metallised
Any dielectric, any manufacturer.
MKT, MKP, MKS, and many others.

Avoid hand wound exotics.

For filter duty the requirements change a lot.
polystyrene, polypropylene, teflon and a few other plastic film types are good.
Some non plastic are also good, eg. silvered mica and NP0/C0G ceramic are two that I know perform well in filters.
 
2 picoDumbs

2 picoDumbs

Member
Joined 2013
KatieandDad said:
I didn't hear a difference between using the Salas Shunt Reg and an LM317 supply.

There will always be a lot of subjective placebo affect in any build.
Click to expand...

Spec/Performance wise Salas shunt reg is far superior than LM317. Whether you would hear a difference would depend on the application and whether you have any other weak links in your audio chain.
Or maybe the performance is beyond being audible, sought of like the difference between 0.001%THD and 0.0001%THD it's unlikely to be audibly different all things being equal.

The B1 is unity gain so noise is unlikely to be an issue. If it was a high gain preamp things would likely be quite different I suspect.
 
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J

jps1964

Member
Joined 2013
The 1µ0 capacitors:
- V-CAP TFTF dia.27x48mm,
- V-CAP OIMP dia.15x36mm,
- AUDIO-NOTE Copper Foil dia.35x53mm,
- AMTRANS AMCO rect.36x32 height 30.5mm,
- ClarityCap MR dia.26x40mm,
- ClarityCap ESA dia.20x38mm,
- ClarityCap SA dia.22x39mm,
- Auricap XO dia.18x20mm,
- JB Capacitor JFX dia.11x22mm,
- Jantzen MKT rect.25x15 height 9mm,
- Jantzen Cross Cap dia.11x24mm,
- Jantzen Z-Cap dia.19x43mm,
- Jantzen Silver Z-Cap dia.19x43mm,
- Jantzen Gold Z-Cap dia.19x43mm,
- Jensen JAC dia.30x71mm,
- Jupiter HT dia.27x40mm,
- Jupiter JCW dia.34x54mm,
- Leclanché Signal Path rect.46x20 height 15mm,
- Obligatto Gold Premium dia.20x35mm,
- MusiCap dia.15x60mm,
- Rike S-Cap dia.25x35mm,
- Hovland SuperCap dia.20x45mm,
- MUNDORF MCAP EVO dia.25x16mm,
- MUNDORF MCAP Suprême Oil dia.36x38mm,
- MUNDORF MCAP MKP dia.11x23mm,
- MUNDORF ZN dia.22x45mm,
- MUNDORF Suprême dia.20x39mm,
- MUNDORF Sup SO, SG, SGO dia.31x42mm.

Type missing before I start with the 10µ?

Definition of the percentiles coming...
 
R

Russellc

Member
Joined 2003
Paid Member
2 picoDumbs said:
B1 is mostly insensitive to power supply quality cause it's unity gain.
You are mostly attenuating a 2Vrms signal ie signal through the active components is high. So signal to noise is already good
Click to expand...

Oddly, I noted quite an improvement going to the regulated power supply 6L6 used in his "Build Thread" as compared to both laptop supply and batteries. Very surprising compared to batteries, not so much of a surprise over the laptop supply.

Russellc
 
2 picoDumbs

2 picoDumbs

Member
Joined 2013
Russellc said:
Oddly, I noted quite an improvement going to the regulated power supply 6L6 used in his "Build Thread" as compared to both laptop supply and batteries. Very surprising compared to batteries, not so much of a surprise over the laptop supply.

Russellc
Click to expand...

You might have had a bad quality switching supply.
I've compared mine with lab power supply which uses lm devices, batteries, and a good quality medical grade switching supply. On those specific setups there was no real difference.
It's very easy to have a bad switching supply though, many are terrible.
 
R

Russellc

Member
Joined 2003
Paid Member
2 picoDumbs said:
You might have had a bad quality switching supply.
I've compared mine with lab power supply which uses lm devices, batteries, and a good quality medical grade switching supply. On those specific setups there was no real difference.
It's very easy to have a bad switching supply though, many are terrible.
Click to expand...

The laptop supply sounded worse which was no surprise...the surprise was how much better the regulated supply sounded compared to batteries.

Russellc
 
2 picoDumbs

2 picoDumbs

Member
Joined 2013
Russellc said:
The laptop supply sounded worse which was no surprise...the surprise was how much better the regulated supply sounded compared to batteries.

Russellc
Click to expand...
Might have something to do with output impedance vs frequency many batteries don't give you a nice flat output impedance vs frequency. Actually I'm not sure whether that would be relevant on B1 with single ended powersupply where current is constant.
Possibly try the battery with a nice big cap across it.
Battery could be noisy too.
I don't doubt your results there is much to be gained through careful attention to power supply performance.
 
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R

Russellc

Member
Joined 2003
Paid Member
2 picoDumbs said:
Possibly try the battery with a nice big cap across it.
Battery could be noisy too.
Click to expand...

Very likely. Someone posted when I noted this before, maybe on this B-1 thread, an article where someone was getting results more quiet with regulated than they did with batteries, which surprised me. My B-1 is fine for my uses with 6L6's regulated version on Peter Daniels board, so I will be leaving it as is. I have found the BA-3 as pre amp to be much superior, so the B-1 is a spare.

Liked the BA-3 as pre amp so well I am building another to go with the F-6, once DIYaudio store (and my play money) chassis stocks are refilled. My other BA-3 pre serves duty in another system along with BA-3 Power amp.

B-1 is relegated to use with F-5 in another system (a combination I dont really care for, but using very efficient speakers seems to help) in a different room. With less efficient speakers, the F-5 shines better (for me anyway) with a preamp that has some gain.

Russellc
 
J

jps1964

Member
Joined 2013
The 10µ capacitors:
- V-CAP TFTF nada,
- V-CAP OIMP dia.25x52mm,
- AUDIO-NOTE Copper Foil nada,
- AMTRANS AMCO nada,
- ClarityCap MR dia.50x65mm,
- ClarityCap ESA dia.45x45mm,
- ClarityCap SA dia.49x46mm,
- Auricap XO dia.34x33mm,
- JB Capacitor JFX dia.25x31mm,
- Jantzen MKT rect.25x22 height 15mm,
- Jantzen Cross Cap dia.26x36mm,
- Jantzen Z-Cap dia.46x70mm,
- Jantzen Silver Z-Cap dia.46x70mm,
- Jantzen Gold Z-Cap dia.46x70mm,
- Jensen JAC nada,
- Jupiter HT nada,
- Jupiter JCW nada,
- Leclanché Signal Path nada,
- Obligatto Gold Premium dia.30x75mm,
- MusiCap dia.37x95mm,
- Rike S-Cap oval to big,
- Hovland SuperCap nada,
- MUNDORF MCAP EVO dia.47x27mm,
- MUNDORF MCAP Suprême Oil dia.66x41mm,
- MUNDORF MCAP MKP dia.24x33mm,
- MUNDORF ZN nada,
- MUNDORF Suprême dia.36x106mm,
- MUNDORF Sup SO dia.46x110mm,
- MUNDORF Sup SG, SGO dia.51x106mm.

Whats about LiFePO4 batteries? 2x VISION (integrated BMS) in serie? Charger from Meanwell...
 

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J

jps1964

Member
Joined 2013
Like this virgin white!

Volume: attenuator, TKD, ALPS...
Coupling capacitors: all (Leclanché, MusiCap and Mundorf in the image)...
Footprint for ELMA switch (2 circuits 12 positions) in process...
Missing charger/batteries switch NE1848, also in process...
--> simplest interconnection!

Last post today, I will go to brasilian restaurant with the family...
 

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2 picoDumbs

2 picoDumbs

Member
Joined 2013
AndrewT said:
No, it is not constant.

The source follower loaded with a CCS pulls a constant quiescent current.

Add on a load and send variable output/current to that load and the supply current varies with the load current.
Click to expand...


I'm pretty sure an amp with a single ended powersupply draws constant current while operating below the bias current. Same thing applies on a balanced amp running dual +/- supply operating below bias current.
The exception is a regular type of amp with +/- supply.
 
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