Dear Apass,
Thank-you for your offer of checking my board. I am just in the process of going over Russ's board to ensure that it tallies up correctly.
I also would appreciate your advice on the possible BC transistor swaps. I currently have BC546 and BC 556, and BC 549 and BC559.
Happy New Year Everyone,
George.
Thank-you for your offer of checking my board. I am just in the process of going over Russ's board to ensure that it tallies up correctly.
I also would appreciate your advice on the possible BC transistor swaps. I currently have BC546 and BC 556, and BC 549 and BC559.
Happy New Year Everyone,
George.
was someone looking for the Threshold 400a amp?
is this it?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=55055&highlight=
allan
is this it?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=55055&highlight=
allan
George,
Actually I haven’t look closely to find a substitution for the MPSA18 since this transistor is easily found, cost pennies and is the suggested substitution by NP.
Most any low power NPN with high DC current gain and low noise will work there for Q1/Q3 but sound wise will be different so the suggestion of the MPSA18 stands.
I looked to the specs of BC devises and didn’t fine a direct substitution but you could try BC550C or BC547C which are closer than others and see if you like them soundwise.
Actually I haven’t look closely to find a substitution for the MPSA18 since this transistor is easily found, cost pennies and is the suggested substitution by NP.
Most any low power NPN with high DC current gain and low noise will work there for Q1/Q3 but sound wise will be different so the suggestion of the MPSA18 stands.
I looked to the specs of BC devises and didn’t fine a direct substitution but you could try BC550C or BC547C which are closer than others and see if you like them soundwise.
steenoe said:Yep, I was
Thanks for the link, Allan.
Steen
steen
we have all seen how fast you are
Have made the pcb's yet
may need a new thread for the 400a?
I have not heard (listen too) the threshold gear.
Can anyone compare this preamp to the cc-ccs-x-bosoz or other
pre's
Or the 400a to a ksa50?
allan
thanks for the description steen
I like the bosoz (with all the suffix'es ) too, also main system.
I may try the NS10.
I like the simplicity of the design.
Problem is
easy to change the character of the sound by using different tranistors.
but to find the best to suit your own preferences.....?
allan
I like the bosoz (with all the suffix'es ) too, also main system.
I may try the NS10.
I like the simplicity of the design.
Problem is
easy to change the character of the sound by using different tranistors.
but to find the best to suit your own preferences.....?
allan
choky said:
first:
you are deep enough in this hobby if you can hear diff between various transistors with your existing equipment;
second-why is this problem-just use sockets for transistors untill you find preffered combinations,then solder them permanently
my quote
"Problem is
easy to change the character of the sound by using different tranistors.
but to find the best to suit your own preferences.....?"
Maybe i phrased this not quite right?
ckoky, what i mean is that all transister parameters are not exactly the same, even between the same makes.
This should have an effect on the circuit.
Sockets, thougth about this, may try it still.
But wouldn't they add capacitance between the contacts? (socket and pin of component)
allan
I wanted to use sockets to begin with. I didnt find them in time so I just soldered in the MPSA18's Dont really feel like taking them out again. I will try some other transistors though, just to see what happens, and for that I would prefer sockets and when testing is done the preferred part is soldered in. I dont think the small parasitic capacitances of the sockets is of big concern for testing purposes. Would be fun to put some J-fets in and see what happens
Steen
Dont really feel like taking them out again. I will try some other transistors though, just to see what happens, and for that I would prefer sockets and when testing is done the preferred part is soldered in. I dont think the small parasitic capacitances of the sockets is of big concern for testing purposes. Would be fun to put some J-fets in and see what happens Steen
awpagan said:
my quote : "just use sockets for transistors until you find prefered combinations"
accent is on "until you find prefered"
in my gadgets (with muuucho less feedback than that overcomplicated and overpriced and over respected lousy NS10 preamp) every different tube origin can have slightly different sound-sometimes better ,sometimes not.
I'm not perfectionist ,but only when I achieve "good'nuff" level of SINGING ,not reproducing musical signal......
you know-its for fun
serious one,but still fun.....
after many (?) years some of my hardest maded devices are still good as in day zero,but now I have much different attitude
so , why not finish post with
Embarrassment and Joy
Hello Folks,
I am overjoyed and yet hanging my head in embarrassment!
My NS10 works (single channel)... nice clean sine wave signals anyway: gotta rush down and plug in lots of loose wires into my Carlos FM chip amp set it up on a big piece of chip board and cover the workings with my wife's washing basket, (after I have hung out the clothes).
I now have a gain of 5.0!
The thing is, that, despite looking at those data sheets multiple times, I STILL got the transistors in back to front!!!!! Combine that with a dud transistor or two (where are these things made?????) and I got totally confused. What finally made me twig was time and writing the CBE onto the tips of my fingers, using my finger nails to represent the flat side of the TO92 package. I think I will use that technique a lot more now that my 3D capacities are obviously failing along with my eye-sight.
I guess then the other things are:
1. My circuit board works nicely and I think is kind of cute and yet versatile. Lots of room for different capacitor types and configurations, several input/output options (pins for the final installation, those little clamps for fiddling around), lots of possible grounding options.
2. Using "Machined Pin IC Socket Strips" e.g.Jaycar version
as the transistor mounts works nicely. If you have a lot of swaps to try, you could even solder the transistor legs into a set of three in a row and piggy-back them into the three mounted on your circuit board.
They could also be useful fine-tuning active crossovers.
Gotta go and reduce the gain on my chip-amp and play a single channel of Pink Floyd right now.
Thank-you all for your perseverance with a real dummy!
Regards,
George.
Hello Folks,
I am overjoyed and yet hanging my head in embarrassment!
My NS10 works (single channel)... nice clean sine wave signals anyway: gotta rush down and plug in lots of loose wires into my Carlos FM chip amp set it up on a big piece of chip board and cover the workings with my wife's washing basket, (after I have hung out the clothes).
I now have a gain of 5.0!
The thing is, that, despite looking at those data sheets multiple times, I STILL got the transistors in back to front!!!!! Combine that with a dud transistor or two (where are these things made?????) and I got totally confused. What finally made me twig was time and writing the CBE onto the tips of my fingers, using my finger nails to represent the flat side of the TO92 package. I think I will use that technique a lot more now that my 3D capacities are obviously failing along with my eye-sight.
I guess then the other things are:
1. My circuit board works nicely and I think is kind of cute and yet versatile. Lots of room for different capacitor types and configurations, several input/output options (pins for the final installation, those little clamps for fiddling around), lots of possible grounding options.
2. Using "Machined Pin IC Socket Strips" e.g.Jaycar version
as the transistor mounts works nicely. If you have a lot of swaps to try, you could even solder the transistor legs into a set of three in a row and piggy-back them into the three mounted on your circuit board.
They could also be useful fine-tuning active crossovers.
Gotta go and reduce the gain on my chip-amp and play a single channel of Pink Floyd right now.
Thank-you all for your perseverance with a real dummy!
Regards,
George.
Hello,
I do not want to hijack the thread, but I hope someone can point me in right direction. I am interested in building NS10 in its orginal configuration with single PSU. I found four threads about this preamp, schematic drown by Mr. Pass but with no part values. My electronic knowledge is rather basic, so I am unable to come up with my own circuit simulation. Was full schematic published on this forum?
Thanks
I do not want to hijack the thread, but I hope someone can point me in right direction. I am interested in building NS10 in its orginal configuration with single PSU. I found four threads about this preamp, schematic drown by Mr. Pass but with no part values. My electronic knowledge is rather basic, so I am unable to come up with my own circuit simulation. Was full schematic published on this forum?
Thanks
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