chrismercurio,
My guess is that burn in time would vary depending on the parts used.
I would think that particularly the caps, wire and connectors are going to take the longest to run in.
Once you have a hundred hours on it powered up I would think that it should be pretty well on it's way there. You should get some subtle improvement from that point on but you will get a feel for it's character from the start and it will just get better until it settles in for the long haul.
Keith
"Read 'em and weep
Was her adjustable slogan"
F.Z.
My guess is that burn in time would vary depending on the parts used.
I would think that particularly the caps, wire and connectors are going to take the longest to run in.
Once you have a hundred hours on it powered up I would think that it should be pretty well on it's way there. You should get some subtle improvement from that point on but you will get a feel for it's character from the start and it will just get better until it settles in for the long haul.
Keith
"Read 'em and weep
Was her adjustable slogan"
F.Z.
I replaced my wallwart with a pair of 9V batteries for test...much improved!
I also lowered the output resistor from 1k to 100R.
Since the new search function is worse than the old search function, what are the favorite 1uF and 10uF caps for the B1? I am using the models specified by Nelson with a small bypass PAS cap on the AXON 10uF.
Thank you,
Chris
I also lowered the output resistor from 1k to 100R.
Since the new search function is worse than the old search function, what are the favorite 1uF and 10uF caps for the B1? I am using the models specified by Nelson with a small bypass PAS cap on the AXON 10uF.
Thank you,
Chris
Ask 10 different DIY'ers and you'll get 10 different answers. Personally I'm using Mundorf standards in those positions, and I have no complaints, however I've not done any comparisons, so perhaps I don't know what I'm missing.
-j
Hi all
My first post so be gentle
twisted tale of a solid state novice.
I was looking for a simple pre to build as a birthday gift for my brother and remembered hearing a home brew B1 at a Hi fi meet some time back. So off I went to Pass diy’s web site to find the details. I built it with a Teddy reg and plugged it in to my setup (all home built tubes and a pair of Fostex based OB’s) just to make sure all was well. I had a bit of a listen and thought hey this sounds good in fact it sounds very good. I must say that my buttom lip quivered when it went off to my brother (happy birthday err not
). I missed that pre with all it’s detail and drive so much I built one of my own (well two actually but that’s another story) and then I found this thread (always last on the bus
).
I’ve had some fun trying different caps and resistors from my parts bin. Maplin, Ansar Super sounds, Clarity MX and ESA, Mundorf ZN and Mundorf Silver Oils for C100-C200. I did not really notice a great difference swapping between Polly caps with ZN’s to my ears sounding best for clarity. Then I swapped in the Silver Oils, wow they really did it for me. A great sounding cap which I have used many times in my tube builds. For C101-202 I used a pair of Clarity Cap MX which I had to hand. R102-202 and 104-204 are Vishay bulk foils from the said parts bin. The volume pot is a Vishay shunted 20k Alps blue. (Big parts bin = Big mistakes
)
I’m really happy with my B1 it sounds great
Now I have a spare set of TVC’s to try driving a B1 with.
Phono stage next, any ideas?
Mr Pass I thank you and my brother thanks you also.
Nice place you all have here
Any one in the west midlands area of the UK?
My first post so be gentle
twisted tale of a solid state novice.
I was looking for a simple pre to build as a birthday gift for my brother and remembered hearing a home brew B1 at a Hi fi meet some time back. So off I went to Pass diy’s web site to find the details. I built it with a Teddy reg and plugged it in to my setup (all home built tubes and a pair of Fostex based OB’s) just to make sure all was well. I had a bit of a listen and thought hey this sounds good in fact it sounds very good. I must say that my buttom lip quivered when it went off to my brother (happy birthday err not
). I missed that pre with all it’s detail and drive so much I built one of my own (well two actually but that’s another story) and then I found this thread (always last on the bus). I’ve had some fun trying different caps and resistors from my parts bin. Maplin, Ansar Super sounds, Clarity MX and ESA, Mundorf ZN and Mundorf Silver Oils for C100-C200. I did not really notice a great difference swapping between Polly caps with ZN’s to my ears sounding best for clarity. Then I swapped in the Silver Oils, wow they really did it for me. A great sounding cap which I have used many times in my tube builds. For C101-202 I used a pair of Clarity Cap MX which I had to hand. R102-202 and 104-204 are Vishay bulk foils from the said parts bin. The volume pot is a Vishay shunted 20k Alps blue. (Big parts bin = Big mistakes
)I’m really happy with my B1 it sounds great
Now I have a spare set of TVC’s to try driving a B1 with.
Phono stage next, any ideas?
Mr Pass I thank you and my brother thanks you also.
Nice place you all have here
Any one in the west midlands area of the UK?
The power supply sweet spot...and AVC/TVC's
My die hard tubefile friends are so impressed with the sound of this they want me to build a few more of these.
So...
the battery supply kicks the crap out of the wall wart in the 2 different rooms/systems I have tried it in. I ran it at both 9V and 18V and while 18V provides a much more articulate soundfield and low end, the midrange and top end are better at 9V. Has anyone played with the points in between to find the "ideal"? I know I'm on thin ground on this one with some of you, but I seem to recall Salas and some others playing with this many moons ago.
I'm using a PEC pot on mine, but am curious if anyone has tried a TVC or AVC from the various makers in their B1?
Thank you in advance,
Chris
My die hard tubefile friends are so impressed with the sound of this they want me to build a few more of these.
So...
the battery supply kicks the crap out of the wall wart in the 2 different rooms/systems I have tried it in. I ran it at both 9V and 18V and while 18V provides a much more articulate soundfield and low end, the midrange and top end are better at 9V. Has anyone played with the points in between to find the "ideal"? I know I'm on thin ground on this one with some of you, but I seem to recall Salas and some others playing with this many moons ago.
I'm using a PEC pot on mine, but am curious if anyone has tried a TVC or AVC from the various makers in their B1?
Thank you in advance,
Chris
If you know your target output voltage and the load value,
you can tweak the supply for minimum distortion with any
given JFET. I have a short article coming up next month,
called "The Sweet Spot"
looks like I spoke out of turn and needed to wait...
I tried 2 in series and 2 in parallel. (It's an easy swap.) This is how I did the 9V and 18V listening.
Still curious about the best supply operating point and if I can use an AVC/TVC in lieu of a pot. Guess I could bust out a bunch of 1.5V batteries and start adding them to the mix...with a distortion analyzer (which I would need to borrow).
Still curious about the best supply operating point and if I can use an AVC/TVC in lieu of a pot. Guess I could bust out a bunch of 1.5V batteries and start adding them to the mix...with a distortion analyzer (which I would need to borrow).
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I tried that...you gotta be careful with 9V off the shelf batteries. They pop, get really hot, and do funny stuff (not a technical term by any means) when a bunch of them are connected together in series or in this case series parallel. Besides, the 9v battery has more than enough current delivery for a 40mA draw.
So does an 800VA transformer in a preamp. Naim Audio
Naim feel oversizing transformers makes a difference to their preamps, even though they probably run on less than 100mA.
I am pretty certain if you give it a go (even if it is only temporarily) you will hear a difference/improvement.
Ultimately I will probably go SLA on the battery front with as you said, higher current. I will keep you posted. In the meantime, can you try it?
I plan on buying a pair of tvc's for a different project and wanted to know if they will work...will look at the lightspeed again.
Fran,
Have you tried a battery?
Ah, ok. It'd be great to hear how the TVC works out. I have had some (limited) experience of the music first TVC pre (based on stevens and billington Tx I think and retailing for about £2000) and I wasn't hugely impressed with it. Well, it was good, but not as good as you would think. I would think that theres a fair bit in optimising the input and outputs to get the best out of them.
I haven't tried a battery - but after reading your posts its high on my list. I have some LiPo 3.3V batteries here and I might just hook them up to give me 24V for the B1. I also have some of the shunt regged B1 boards coming so that would also be an interesting comparison.
keep us posted!
Fran
I haven't tried a battery - but after reading your posts its high on my list. I have some LiPo 3.3V batteries here and I might just hook them up to give me 24V for the B1. I also have some of the shunt regged B1 boards coming so that would also be an interesting comparison.
keep us posted!
Fran
the output cap needs to charge to the FET voltage.
During this charge up time the output offset cannot be zero.
A resistor to hold the output at DC ground will help reduce the charge up time slightly, but a mute is required to ensure zero offset during start up if using a single supply, rather than a dual polarity supply.
During this charge up time the output offset cannot be zero.
A resistor to hold the output at DC ground will help reduce the charge up time slightly, but a mute is required to ensure zero offset during start up if using a single supply, rather than a dual polarity supply.