the output could be unstable if directly connected to a cable/load.
So you use a resistor to help isolate the output from the reactance in the load.
So you use a resistor to help isolate the output from the reactance in the load.
By duplicate, do you mean another 1K resistor in parallel with the existing 1K, or is it in series with the 1K resistor?
I am hoping I can just modify the splitter outside the B1 and not change anything inside the B1.
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Thanks, that means, it is an inside the box modification then. Thus, I have to mod the board to accommodate 4 RCA sockets.
Is there a way I can modify the RCA splitters outside the box and leave the B1 as is? Sorry for all the noob questions. Electronics definitely not my strong point.
Is there a way I can modify the RCA splitters outside the box and leave the B1 as is? Sorry for all the noob questions. Electronics definitely not my strong point.
look at the schematic, the 1k goes to the cap and the 221k to signal ground. You cant (afaik) do this with the cable outside the case.
" Is there a way I can modify the RCA splitters outside the box and leave the B1 as is? "
perhaps you can use a split cable (dual line cable).......
one cinch ---two cable----two chinch on the other end.......per channel.
perhaps you can use a split cable (dual line cable).......
one cinch ---two cable----two chinch on the other end.......per channel.
Hi all,
I've got some Toshiba 2sk209. They are SMD, slightly lower transconductance than 2sk170 and lower noise. Could they be used for a B1 like buffer? Thanks
I've got some Toshiba 2sk209. They are SMD, slightly lower transconductance than 2sk170 and lower noise. Could they be used for a B1 like buffer? Thanks
what grade are these?.........bl?
have you measured them?
datasheet stated it is a low noise audio transistor.
if you have them on hand.......you can build a buffer preamp.
but take care not to exceed the maximum power dissipation!
2sk209 only around 120mW at higher room temperature.......
2sk170 up to 400mW maximum.
have you measured them?
datasheet stated it is a low noise audio transistor.
if you have them on hand.......you can build a buffer preamp.
but take care not to exceed the maximum power dissipation!
2sk209 only around 120mW at higher room temperature.......
2sk170 up to 400mW maximum.
They are BL. I have 20 of them. Bought from Mouser few years ago. I run few sims in spice during lunch time. output impedance and distortion are very similar to 2sk170. Freq response extends to higher frequencies so may have to limit it by changing something, the resistor at input I would guess
Maybe reduce the Vce to around 8V as done with the sot23 BF862.
And maybe reduce the Id by fitting a source resistor to both upper and lower devices as shown in D.Feucht
Thanks for the linked document.
I will measure them first and see where I land with dissipation.
I will also consider large copper area to ease heat exchange
Maybe this question has been answered somewhere in this thread - if, so, my apologies, but has anyone compared the first generation with two 2SK170s to the complementary version with the 2SK170/2SJ74?
Does one sound "better" than the other?
Does one sound "better" than the other?
I wouldn't say one is "better" than the other. If anything the complementary version is more neutral, which I know probably sounds weird, as the original was pretty neutral to begin with - I guess what I mean is that it seems to just disappear after a while. I felt on direct comparison the V2 seemed a little warmer sounding, but that might depend on the output caps you're using on the original (mine are Jupiter bypassed with 0.1uF FT-3 teflon). Maybe Vince could weigh in a little here since he's heard my unit for a while.
I'm going to say they sound the same.
That would mean using them in the same circuit design twice. Only a handful of people could probably tell you the outcome.
From what I've read, a lot of care was taken to recreate both N-ch and P-ch jfets.
The P-ch took longer to bring to market by Linear Systems. They put much effort in getting it right.
Fair enough. Maybe the deciding factor will be whether you want to spend money on good output caps! Vince has nice ones in his original too.
Just saw Schubert's post...
I heard the Rev2 and I have the Rev1 with outrageously priced caps and naked Vishays in the signal path with original Toshibas. They both sound really transparent to me. I would prefer anything without caps, if possible. However, I think caps get a bad rap and using expensive ones aren't really that necessary. There's a bunch of great caps out there for little money. Motor run caps are said to be as good as some high-end caps. But, I'm getting off topic.
if you are getting different sound from same design with Toshibas vs LS jfets, I'm going to say the sound difference is incredible subtle. Difference could all be in your head too
The best place to try both is in the B1 rev1 or rev2 for sure. Can't get much simpler.
Just my 2 cents.
Vince
I heard the Rev2 and I have the Rev1 with outrageously priced caps and naked Vishays in the signal path with original Toshibas. They both sound really transparent to me. I would prefer anything without caps, if possible. However, I think caps get a bad rap and using expensive ones aren't really that necessary. There's a bunch of great caps out there for little money. Motor run caps are said to be as good as some high-end caps. But, I'm getting off topic.
if you are getting different sound from same design with Toshibas vs LS jfets, I'm going to say the sound difference is incredible subtle. Difference could all be in your head too
The best place to try both is in the B1 rev1 or rev2 for sure. Can't get much simpler.
Just my 2 cents.
Vince
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Well, I'm a little embarrassed. I thought you were talking about the difference between Toshibas and Linear system jfets. You are asking the difference between B1 V1 and V2.
Adding to what I already said- I felt I was getting a little more output from rev2 somehow. Could just have been the pots used in each version. It was definitely a "more volume" thing and not a "has more detail" thing.
I think it's fair to say the rev2 has an advantage in a more direct signal path. If you are looking to tailor the sound to a certain timbre, use v1 and try different caps and resistors. For really great transparency, build v2.
Interesting fact: you can turn up both versions fully open and there's no noise and distortion.
Adding to what I already said- I felt I was getting a little more output from rev2 somehow. Could just have been the pots used in each version. It was definitely a "more volume" thing and not a "has more detail" thing.
I think it's fair to say the rev2 has an advantage in a more direct signal path. If you are looking to tailor the sound to a certain timbre, use v1 and try different caps and resistors. For really great transparency, build v2.
Interesting fact: you can turn up both versions fully open and there's no noise and distortion.
Thanks for the counsel.
I am using the complimentary version and wondered if there could be some advantage to version one.
To show my ignorance I was thinking that there was a way using bipolar supplies to not have to use an output cap, just a trimpot like with the complementary version.
Caps can get expensive! If one has to use caps with the single-ended version I will stick with the complementary.
Glad to hear the differences are miniscule.
I am using the complimentary version and wondered if there could be some advantage to version one.
To show my ignorance I was thinking that there was a way using bipolar supplies to not have to use an output cap, just a trimpot like with the complementary version.
Caps can get expensive! If one has to use caps with the single-ended version I will stick with the complementary.
Glad to hear the differences are miniscule.
I re-read my email to Schubert describing what I thought after I heard them both. I was definitely leaning toward the B1 v2.
My B1 has over $600 in caps in it. I didn't pay for them, someone else did; I wouldn't spend that much. I can do a lot with $600. 😉
Vince
My B1 has over $600 in caps in it. I didn't pay for them, someone else did; I wouldn't spend that much. I can do a lot with $600. 😉
Vince