| Russ White |
Hello all,
Tony and others have asked me to look over the NS10, so I did. I managed to find Nelson's schematic, but it is lacking values and ratings for parts. So I just threw something together hoping Nelson and the rest of you could help fill in the blanks.
Some questions:
1) What should the PS be.
2) What are the part values.
3) What other design factors should I consider.
So to get things rolling I submit what is likely a completely flubbed up layout:
Cheers!
Russ |
|
|
| Russ White |
| And my first attempt at the schematic: |
|
|
| apassgear |
| quote: | Originally posted by Russ White
Hello all,
Tony and others have asked me to look over the NS10, so I did. I managed to find Nelson's schematic, but it is lacking values and ratings for parts. So I just threw something together hoping Nelson and the rest of you could help fill in the blanks.
Cheers!
Russ |
Good you did open this thread, you won me but I'm glad you did.
I wanted to post a GUESS WORK schematic with some values to gather some interest and maybe having others like Blues running a virtual test. Of course we would like Nelson throughing in all his knowledge and memory of it, unfortunately he does not have the original schematic.
One thing for sure, Nelson has tiped that the NPN devices should now be MPSA18 (On-Semi). I check on this and it is a modern replacement of the original MPS6571 same low noise and equal in most parameters with the added benefit of a higher voltage rating, VCEO and VCBO up to 45.
:cool: |
|
|
| Russ White |
Ok I found lumanauw's excellent instructions:
| quote: | If you are a "dumb", then I'm the "dumber"
You got the blind NS10 schematic in your hands?
If you do, then here's what I do.
-First, I use symmetrical power supply, +/-25V with 0 gnd. So, I do not use R5, R6, R7 in the schematic. If you got only single supply 0/50V, then R7=200k, R5=R6=100k, C4=47uF.
- R13=20k potentiometer, for volume adjust. The wiper goes to left of C1 (470nF MKT), R12 is moved after C1. The bottom of VR13 goes to ground via additional 1k resistor, the upper is fed with input.
-The right of C1 connected to voltage divider (R6-R7), thus to R12=1k, and this R12 connects to gate of Q1, or if you got symmetrical supply, you can put the right of C1 with 100k to gnd (0V).
-R12=1k, is placed after the voltage divider (that is after C1) and before the gate of Q1 (2sk30y).
-I also put 470pf WIMA from gate to drain of Q1 (2sk30y).
-R4=10k, Q2=mpsA92, Q3=mpsA42, R8=470ohm, C2=C3=22uF non polar elko. R1=10k, R2=2k2 (makes gain=10k/2k2), R9=2k7 1/2watt.
- put base stopper at base of Q3, I use 1k there.
- R3 is for adjusting DC output, it is about 100k-470k, depends what device you use for Q1. I myself don't mind DC offset at left of C2, I got only 0V5 there, so I don't use R3. Sounds better without R3, even it has DC.
-R10=100ohm, R11=100kohm.
I tried various devices for Q1, MPSA06, MPSA42, 2n5401, BC550C, BC546, they sound differently. The best sound is 2sk30y (you can also buy 2sk30gr suffix). |
And I have attempted to do a bipolar schematic, but I am affraid I have botched it. Especially I am worrind about what should be connected to the negative rail.
Please bear with my ignorance. This is a learning expedition for me. :)
Cheers
Russ |
|
|
| apassgear |
You are right:D
On post 11 Lumanauw gives values for a double rail NS10.
So if we are doing it a double rail (+-25V) we have a very good staring point from a working clone.:) |
|
|
| steenoe |
Maybe it would be possible to convince some of the owners to take the lid off, and do a little investigation?
Steen:) |
|
|
| apassgear |
I guess this is the circuit that Tom (tmblack) is mentioning on the other NS10 thread (NAC 32?) or NA321?. This one uses a CCS.:cool:
PD Sorry, the file is to big for posting |
|
|
| Russ White |
So does anyone know where the negative rail connects to the circuit? Did I do it correctly?
Thanks,
Russ |
|
|
| Nelson Pass |
There is only a positive rail and ground in the original, in
case this is a point of confusion. |
|
|
| Russ White |
| quote: | Originally posted by Nelson Pass
There is only a positive rail and ground in the original, in
case this is a point of confusion. |
Thank you, I think I have the original circuit figured out pretty well, but I was trying to make a bipolar power supply version as well.
Cheers!
Russ |
|
|
| choky |
gentlemans-my modest (and verry clever ;) ) proposal is that we merge this in just one thread......not sorta Krell clone thread but.....
besides -even if NS 10 is JUST preamp ,I think that this preamp deserves clonnin' thread ........hehe
just notice- I always have strange way in making system for particular room-I choose first speakers for room,then preamp,and then amp ;
Am I weird or what -preamps are offten bigger fetish for me than amps ,mebbe just because I always have more than one good amp ..... |
|
|
| lumanauw |
Hi, Russ,
About the schematic in post #5 :
- If you use single supply (only + and gnd), this schematic is lacking the pull up section (R5,R6,C4 in NP's sch). If the Q1's base voltage is not defined (near middlle of the rail, usually), I'm afraid the whole thing won't work.
-RBS (of Q3) is not attached to ground, but in series with the base (ordinary base stopper configuration)
For using symmetrical power supply, then your schematic in post#5 can have the input section like that (without R5,R6,C4),
-R13 is connected to GND (to define 0 point for Q1)
-R3 is connected to -rail (adjusted in value until you get 0V on output),
-The end of C3 is also connected to GND
-R9 is connected to -rail
-R11 connected to GND
I don't advise the following, but I do this : I pick up transistors with lower gain (HFE) in position of Q2 and Q3. I use MPSA42 and MPSA92 there. I don't use R3. If you trace oscilation in the whole cct, you can put pF capacitor between B-C of Q1.
PS :
Mr.Pass, is it alright to make this schematic using symmetrical power supply? I hope I'm not Hi-Jacking your NS10, it is just because I don't have the original component values |
|
|
| Russ White |
| quote: | Originally posted by lumanauw
Hi, Russ,
For using symmetrical power supply, then your schematic in post#5 can have the input section like that (without R5,R6,C4),
-R13 is connected to GND (to define 0 point for Q1)
-R3 is connected to -rail (adjusted in value until you get 0V on output),
-The end of C3 is also connected to GND
-R9 is connected to -rail
-R11 connected to GND
I don't advise the following, but I do this : I pick up transistors with lower gain (HFE) in position of Q2 and Q3. I use MPSA42 and MPSA92 there. I don't use R3. If you trace oscilation in the whole cct, you can put pF capacitor between B-C of Q1.
|
Thanks!
My question, and that schematic is for dual supply (bipolar).
You have helped me greatly.
Cheers!:drink:
Russ |
|
|
| Russ White |
| here is an attempt at a single side bipolar layout, mostly just so I can build a prototype: |
|
|
| Russ White |
| Here is the schematic: |
|
|
| lumanauw |
Hi, Russ,
What's the purpose of C4 (connected B-E)? |
|
|
| Russ White |
Oops!
Thanks, that was a mistake. It was meant to be between B-C of Q1 as you earlier suggested as optional to control oscillation.
Corrected schematic: |
|
|
| Russ White |
| And here is the corrected layout. :) |
|
|
| Russ White |
| for +/-25V supply: |
|
|
| steenoe |
| quote: | | Single Side Layout Take II |
Russ, thats pretty neat. Cant help thinking, if I had a PDF I would etch a couple right away:D
Steen. |
|
|
| jacco vermeulen |
Steen,
you're a mind reader.
Goodlooking boards, Russ. |
|
|
| Russ White |
Thanks guys, you are very kind. Always glad to share.
Here you go! :)
Note I changed the PCB a bit. I used actual traces for the GND return traces instead of a copper pour.
Cheers!
Russ
Here is the copper side, it is not reversed. |
|
|
| Russ White |
Here is the component side.
It is reversed for toner transfer. |
|
|
| steenoe |
Thanks a lot Russ, most kind of you:)
What is the excact measure of the board?
Steen:cool: |
|
|
| Russ White |
No problem Steenoe. :)
The PCBs are 2.1250" x 2.4500"
Cheers!
Russ |
|
|
| Russ White |
Here is the schematic - cleaned up. :)
Cheers!
Russ |
|
|
| sdman |
What was the voltage for the original single rail NS10?
thanks
sdman |
|
|
| apassgear |
Russ,
It would be a nice touch if you could squeeze in a small cap at each rail, say 1000u @ 35V on the board, similar at what you did on the xbosoz. :) |
|
|
| Russ White |
| quote: | Originally posted by apassgear
Russ,
It would be a nice touch if you could squeeze in a small cap at each rail, say 1000u @ 35V on the board, similar at what you did on the xbosoz. :) |
Ok, no problem, fighting a production work issue here, give me a couple hours. :) |
|
|
| Russ White |
Hi all, there is an error around Q2 on the PDFs. Do not use them I will post fixed PDFs shortly with Tony's bypass caps added.
Sorry if any of you started etching already. a fix is easy, just use a sharpy to make a trace to the positive rail, or if you already etched, just make a wire jumper or solder bridge to the positive rail.
Sorry, should have looked closer before posting. |
|
|
| Russ White |
New PCB size is 2.175" x 2.45"
Here is the corrected copper side with Tony's bypass caps: |
|
|
| Russ White |
Mirrored for toner transfer.
Notice I added pads for alternative cap sizes.
I also move some resistors to space them for easier soldering. Less risk of solder bridge. |
|
|
| apassgear |
Thanks Russ.
For some reason C1 seems small for a bpt maybe ok for jfet, can someone chip in with some insight?:confused: |
|
|
| Russ White |
| Hmmm its the standard TO-92 package. |
|
|
| steenoe |
| quote: | | For some reason C1 seems small for a bpt maybe ok for jfet |
Yes, I noticed that too. I would have preffered at least 1uF for C1. Also C2 being an electrolytic isn't excactly my cup of tea. Maybe a Black Gate NP:D would be in order:)
Steen:) |
|
|
| Russ White |
| quote: | Originally posted by steenoe
Yes, I noticed that too. I would have preffered at least 1uF for C1. Also C2 being an electrolytic isn't excactly my cup of tea. Maybe a Black Gate NP:D would be in order:)
Steen:) |
I used the values lumanauw provided. But that is a 15mm spot, so I know I could find at least 1uf MKP to fit, and even 2uf MKT.
Values given should be looked at as guidlines. :)
I have not even built one yet, so I have no idea how it will work.
Hopefull one of you folks can fill me in. :) |
|
|
| Russ White |
| BTW I am happy to redo the PCB with an even bigger C1 if you like. |
|
|
| apassgear |
| quote: | Originally posted by steenoe
Also C2 being an electrolytic isn't excactly my cup of tea. Maybe a Black Gate NP:D would be in order:)
Steen:) |
Yes, C2 and C3, unfortunately I don't use BG np's.
But hopefully we will be able to skip output cap if we manage to have a very low drift on the double rail set up, which I doubt though.
C2 will greatlly determine the overall sound signature and balance through the audio spectrum:) |
|
|
| steenoe |
| quote: | | It would be a nice touch if you could squeeze in a small cap at each rail, say 1000u @ 35V on the board |
I think Tony meant 1000uF, could be wrong.
I would like C1 with pin dist 21,5mm but you don't have to redo the board just because of that:)
| quote: | | Hopefull one of you folks can fill me in. |
I intend to make a couple of boards and hopefully stuff them next week. Will keep you posted, ofcourse:)
Steen:) |
|
|
| apassgear |
| quote: | Originally posted by steenoe
I think Tony meant 1000uF, could be wrong.
I would like C1 with pin dist 21,5mm but you don't have to redo the board just because of that:)
Steen:) |
That's correct. 1000uf. Specially if we are using only one PSU for both channels. |
|
|
| Russ White |
| Ahh ok, I will rework things and post a PIC and see what you all think, then more PDFs. :) |
|
|
| apassgear |
| quote: | Originally posted by Russ White
Ahh ok, I will rework things and post a PIC and see what you all think, then more PDFs. :) |
If you can keep the film bypass better still. |
|
|
| Russ White |
| Why don't you all propose some ideas for C2 andC3. :) So I can keep the rework down. :) |
|
|
| steenoe |
| quote: | | C2 will greatlly determine the overall sound signature and balance through the audio spectrum |
Is there any particular reason for C2 being 22uF, wouldnt 5-10uF be enough?
It would be easier to fit a nice sounding polyprop then.
Steen:)
Edit.| quote: | | I would like C1 with pin dist 21,5mm |
Its 22,5mm. |
|
|
| apassgear |
| quote: | Originally posted by steenoe
Is there any particular reason for C2 being 22uF, wouldnt 5-10uF be enough?
It would be easier to fit a nice sounding polyprop then.
Steen:)
|
C2 will have a great impact on the over all sound. Other similar circuits go fron 22 or 47 and up to even 100uf on that position but of course it depends on topology and active devices used. I suspect that it wont do with less than 22, but as always is a matter of testing for the best sound and taste
:) :) :) |
|
|
| steenoe |
Thanks for enlightening on that, Tony. Since C2 and C3 are Non polar, what about using two normal electrolytics turning in opposite directions? That way you can make a DIY nonpolar. It would be easier (and cheaper) to use good audio components then. Just a thought:)
Steen:) |
|
|
| apassgear |
Uppppps!!!
I was refering to C3 on the FB, sorry.
C2 is the output cap and the size is determined by the amp input impedance. The lower the impedance the bigger the cap. For the F2 you would only need some 2uf i guess. For a more universal type of preamp use 10 or 20uf. |
|
|
| jacco vermeulen |
| quote: | Originally posted by apassgear
Uppppps!!! |
Thanks, i've been scratching my head and rolling my eyeballs for an hour or so. :clown: |
|
|
| BrianDonegan |
Hey Jacco-
Long time, how goes it? |
|
|
| apassgear |
Steen,
Forgot that the F2 uses an input cap so you might as well delete the output cap for that application. BTW, that applies for any amp using an input cap. |
|
|
| steenoe |
Yes, Tony you are right about the F2:) I think this little linestage can come in handy for several uses. (If it sounds good:D ) I consider building one into my headphone amp as one possibility.
What do you think of my suggestion, using two normal electrolytics? Or should we just keep the NP's?
Steen. :) |
|
|
| apassgear |
| quote: | Originally posted by steenoe
Yes, Tony you are right about the F2:) I think this little linestage can come in handy for several uses. (If it sounds good:D ) I consider building one into my headphone amp as one possibility.
What do you think of my suggestion, using two normal electrolytics? Or should we just keep the NP's?
Steen. :) |
Don't think the NS10, as is, has enough power for phones. I guess a push pull type without output cap will be better. I'm sure you will like the F2 for phones:D
Sure, you can use lytics for C2/C3. I know you use very nice caps on your projects so go ahead and try some. Panasonic's FC comes to mind or other similar quality.
For C2 –output cap- make sure you have some positive bias to the + of the cap.
:cool: :cool: |
|
|
| apassgear |
| Sorry Steen, you ment to control your hedphone amp with the NS10, that sounds good jejej. |
|
|
| Russ White |
So, why don't you guys give me some suggestions for lead spacing for C1 C2 and C3. :)
I will do 5mm PS bypass lytics and keep the film caps too. :)
Cheers!
Russ |
|
|
| apassgear |
| quote: | Originally posted by Russ White
I will do 5mm PS bypass lytics and keep the film caps too. :)
Cheers!
Russ |
That's nice Russ.
What's the spacing for the film leads? |
|
|
| steenoe |
| quote: | | What's the spacing for the film leads? |
I suggested up to 21,5mm for C1, with some smaller options too.
Just checked my local supplier and it seem that a 22uF NP cap is 2,5mm, thats a 35v cap. I would like to see an option for C2 and C3 with two sets of holes, for use with normal electrolytics, if it will not confuse matters. (just point the neg's toward each other) If so 2,0mm leg dist.
Steen.:)
Edit. Forgot, filmcap bypass for C2 and C3. |
|
|
| Russ White |
| quote: | Originally posted by steenoe
I suggested up to 21,5mm for C1, with some smaller options too.
Just checked my local supplier and it seem that a 22uF NP cap is 2,5mm, thats a 35v cap. I would like to see an option for C2 and C3 with two sets of holes, for use with normal electrolytics, if it will not confuse matters. (just point the neg's toward each other) If so 2,0mm leg dist.
Steen.:)
Edit. Forgot, filmcap bypass for C2 and C3. |
Cool :cool: I have some 33uf BP lytics the same size. I had already planed on the 21.5mm caps for you Steen. ;)
Cheers!
Russ |
|
|
| steenoe |
Ok, lets stick with the 2,5mm nonpolar's then:)
Steen.:cool: |
|
|
| apassgear |
| quote: | Originally posted by Russ White
So, why don't you guys give me some suggestions for lead spacing for C1 C2 and C3. :)
Cheers!
Russ |
Let’s see if we get some input from others.
But for the time being I would keep the the 5 mm spacing for C3. A good choice would be a BG NP, second choice Panasonic FC.
Now coming to the output cap C2. It has been a custom for most of us to use the best polyprop (MKP) one can deal with in this position. Space should allow at least for a 10uf Solen brand cap.
Not so sure for what to do with the input cap C1, if needed. I’ll have a look at what was the input impedance of the NS10 was. The input cap will be needed only for sources without an output cap. All of this refers to a double rail NS10.
Ok, I checked the input impedance of the circuit which Threshold (NP) stated at 25K. A 1uf should do then. My take would be a WIMA (MKP again) or similar.
:) |
|
|
| apassgear |
| If someone would like to make a NP cap out of two BP (B2B) you will have to double the capacitance of each BP to end up with the correct amount of capacitance.:D |
|
|
| Russ White |
| Oops, I meant my 33uf are 2.5mm NPs, not BPs |
|
|
| Russ White |
| Getting closer to what you want? |
|
|
| steenoe |
That must be pretty close:) Just to be clear, here is another way to make a non-polar cap. The attached schematic equals approx 22uF NP electrolytic.
You dont have to change the board, Russ, I just want to make sure you get the idea, if you didn't allready;) Made this way, both options are possible. If you wanted to go with the NP, just jumper one set of pads.
Steen.
Edit. Just spotted something. Wouldn't it be possible to connect the two GND tracks from C4 and C5 directly to the GND tracks (the solderpads) of C7 and C6? That would give a bit more distance between the tracks, making it a bit easier to make the boards:) |
|
|
| Russ White |
Hi Steen,
Yes, I knew what you meant about the two polar caps. I have done it before. But there are on the market now quite a few very good non-polars in 2.5 and 5mm. Nichicon Muse comes to mind. Rubycon also has some pretty good ones.
I like to keep my return path to ground seperate as I did, but I would be happy to change it (If I do I will make the path beefier).
The reason for sperate traces to PGND is that the traces have some resistance, and by having multimple caps on the same trace you form a small voltage divider at the cap under a load, which is not really desirable. This is a trick I learned from my firend who does RF circuits, but it works well for audio too. It makes amps less likely to oscillate.
Cheers!
Russ |
|
|
| steenoe |
| quote: | | The reason for sperate traces to PGND is that the traces have some resistance, and by having multimple caps on the same trace you form a small voltage divider at the cap under a load, which is not really desirable. This is a trick I learned from my firend who does RF circuits, but it works well for audio too. It makes amps less likely to oscillate. |
Oh, I see:) I suggest you leave them as they are, then:)
Steen:) |
|
|
| apassgear |
| quote: | Originally posted by Russ White
Getting closer to what you want? |
That board is coming up pretty nice Russ.
I see you have kept the NP output cap. Well this is a proto board and we can’t be too picky. But the way we implement it is the way it will sound and will determine if we like it or not.
I love those separate ground traces, especially for input and output connections, makes a nice star ground.
For the film bypass at the rails, and others, is better to connect the film cap directly to the lytic and not on a separate ground trace. The idea here is that both caps, lytic and film bypass, should work as a single unit as seen by the circuit. So the star ground for a bypassed couple should not apply.
Film bypass for the rail lytic could be a bit bigger, say 0.47uf MKP’s if this can be squeezed in.
And this is a tip for when you implement and test the circuit. Using bypass on C2 and C3 will change the balance of the overall sound, generally thinning it. My pick is usually not adding a bypass there, that’s the reason for using the best caps you have at hand for those.:) :) :) |
|
|
| Russ White |
Ok since two people I trust say use common trace for the PS bypass caps I will do so. :)
As for C2 and C3, should I simple make it the same size as C1? Would that be better? Or, as Steen has suggested, are back to back polarized lytics like Panasonic FCs the best option? If so, should they be the 2.5MM sort or the 5mm sort. I would think 25v-50V types would be ok, right?
Cheers!
Russ |
|
|
| apassgear |
| quote: | Originally posted by Russ White
Ok since two people I trust say use common trace for the PS bypass caps I will do so. :)
As for C2 and C3, should I simple make it the same size as C1? Would that be better? Or, as Steen has suggested, are back to back polarized lytics like Panasonic FCs the best option? If so, should they be the 2.5MM sort or the 5mm sort. I would think 25v-50V types would be ok, right?
Cheers!
Russ |
For this proto board i would leave the B2B lytic option since there is always way to install an output polyprop cap which is way bigger than C1. If you would like to fit it on the board you’ll have to increase the size of it since 22.5 mm is too small. I think it’s not wise to do this at this point.
But I must repeat that if someone is using a lytic as output cap there is no need that this be a NP. Just make sure you add some positive bias to the positive terminal of the cap using the pot provided. Using a BP this way is much better than the B2B suggestion.
For the FB cap my pick would be two 47uf Panasonic FC caps on the B2B configuration. A 47uf @ 35V FC cap is 6.3 mm in diameter with 2.5 mm lead separation.
I would suggest to increase the size of the bypass caps at the rails though
:cool: |
|
|
| Russ White |
| quote: | Originally posted by apassgear
I would suggest to increase the size of the bypass caps at the rails though
:cool: |
To what?
They are current 5mm pitch 13mm diameter. That should be good for 1000uf 50V. |
|
|
| steenoe |
Russ, I think Tony meant C4 and C5:)
Steen:)
Edit. 0,47uF MKP was suggested, I think thats a good starting point. |
|
|
| Russ White |
| Ah ok, so you thing 5,10,15mm combo pads are good? |
|
|
| steenoe |
| quote: | | Ah ok, so you thing 5,10,15mm combo pads are good? |
Yep, that would be great. I agree to leaving the outputcap as it is for now. As for the FB cap you might want to add the B2B option with 2,5 mm pin dist. That way you can try both options and hear what sounds best:) Besides that, I wouldnt shy away, doing a proto of the last posted board;)
Steen:cool: |
|
|
| choky |
just because I came primary from tube (ptp) world ;) ,it's perfectly common sense that both (input and output) caps -in case of bigger size can be in air- one end on pcb,and other end where it belongs - output jack or pot.........
just my two ounces of vacuum........ hehe |
|
|
| Russ White |
Ok guys,
I think I got most of what you said. Please advise. :)
Cheers!
Russ |
|
|
| steenoe |
| quote: | | -in case of bigger size can be in air- one end on pcb,and other end where it belongs - |
Yes, you are right , Choky.
Air suspended polyprops:)
| quote: | | I think I got most of what you said. |
That looks pretty good to me:) Nice job, Russ:cool:
Steen:) |
|
|
| apassgear |
| quote: | Originally posted by choky
just because I came primary from tube (ptp) world ;) ,it's perfectly common sense that both (input and output) caps -in case of bigger size can be in air- one end on pcb,and other end where it belongs - output jack or pot.........
just my two ounces of vacuum........ hehe |
It was just what I did imply. Better explanation, better understanding. |
|
|
| apassgear |
| quote: | Originally posted by Russ White
Ok guys,
I think I got most of what you said. Please advise. :)
Cheers!
Russ |
I agree with Steen, board look very nice now.
Pour your chemicals and start etching!!!:D :D :D
Thanks Russ, excellent work:cool: |
|
|
| choky |
stop
wonderfull
gimme pdf if ya can
if not-it's ok ;)
yo,ppl-I'm too slow with this (time,again!) I need current per stage to think about supply!
:D |
|
|
| tmblack |
| quote: | I agree with Steen, board look very nice now.
Pour your chemicals and start etching!!!
Thanks Russ, excellent work
|
Did anyone else build this and listen to it before committing to design?
Tom
EE |
|
|
| Mark A. Gulbrandsen |
I just finished looking through this thread and the NS-10 seems remotely similar to the ESS preamp to me. Any resemblence... does anyone else know? Its been a long time since I was inside an ESS preamp, about 1974 to be exact.... but it shure looks familiar to me.
Mark |
|
|
| steenoe |
| quote: | | Pour your chemicals and start etching!!! |
Yep, let them PDF's come rollin':D :D I have the psu's for testing made up allready. Its a Zener/emitter follower with a CCS (J511). The psu was developed in the psu department some time ago, by our friend Alcaid, with the help from other authorities.
Have a look:) (Cant help it Tony, I just love to watch them boards grow on my table:D )
Russ, thanks a lot for all your work on this:) Lets hope it sounds as good as it looks:cool:
Steen.:) |
|
|
| Russ White |
Ok Guys, :)
Here is the copper side. |
|
|
| Russ White |
And the componenet side mirrored.
Thanks to everyone. Let me know if there are any issues.
Cheers!
Russ |
|
|
| steenoe |
Thanks a lot, Russ. Are you gonna built it right away?
Steen:) |
|
|
| Russ White |
If I had the transistors I would. :) I have ordered them, but they are not here yet. :(
But very soon!
Cheers!
Russ |
|
|
| apassgear |
| quote: | Originally posted by tmblack
Did anyone else build this and listen to it before committing to design?
Tom
EE |
Tom,
This is just a proto board for testing. Of course the design can be optimized if we where to produce it for something like a GB. But before that point we wanted to take a peek on different issues and have our own test dirve with it.
I know, from the other thread, you have your own iteration with a jfet as a gain device, could you share a shematic of that implementation?
I myself would be very intereste in having a look at it and testing the circuit. I have some hitachi's from an old project that would like to find a home such as an NS10.
:D :D :D |
|
|
| apassgear |
| quote: | Originally posted by Mark A. Gulbrandsen
I just finished looking through this thread and the NS-10 seems remotely similar to the ESS preamp to me. Any resemblence... does anyone else know? Its been a long time since I was inside an ESS preamp, about 1974 to be exact.... but it shure looks familiar to me.
Mark |
Mark,
No idea which was the ESS, that's the brand?
Could you share more information please?
:) :) :) |
|
|
| apassgear |
| quote: | Originally posted by steenoe
:) (Cant help it Tony, I just love to watch them boards grow on my table:D )
Russ, thanks a lot for all your work on this:) Lets hope it sounds as good as it looks:cool:
Steen.:) |
Yes Steen, I know you always have something hiding under your sleeve:clown: :clown: :clown: |
|
|
| tmblack |
Apassgear
my last iteration was back to NS10 original design with schematic already posted.
You can try JFET or even VMOS as Q1 but I think BJT is neutral sounding for me.
Tom
EE |
|
|
| steenoe |
| quote: | | You can try JFET or even VMOS as Q1 but I think BJT is neutral sounding for me. |
I will try some different types out. As Tony, I also have a little supply of some of those Hitachi's.
I have some sk170 and also some of those rare sk369's:) I intend to try out some j110 also, along with the bjt's.
Steen:) |
|
|
| apassgear |
| quote: | Originally posted by steenoe
I will try some different types out. As Tony, I also have a little supply of some of those Hitachi's.
I have some sk170 and also some of those rare sk369's:) I intend to try out some j110 also, along with the bjt's.
Steen:) |
I guess biasing a jfet is different from a bjt that’s why I was asking Tom for some tips. |
|
|
| steenoe |
| quote: | | I guess biasing a jfet is different from a bjt that’s why I was asking Tom for some tips. |
Yes, I guess so too. I have Borbely's writings on Jfets lying somewhere, and was thinking of taking them with me, when I hit the pillow;) Maybe there is something usefull. In the meantime I second you Tony, asking Tmblack for advice on the matter.
Steen:) |
|
|
| jacco vermeulen |
Why not use the 2SK30 ?
Russ,
thanks for changing and sharing your layout, the 4- and 5-pad cap seats look grand. |
|
|
| steenoe |
| quote: | | Why not use the 2SK30 ? |
You are right Jacco. Thats what Lumanauw used, if memory serves me correct. Lets see if the supplier can dig up some of those. The darn thing about these old Toshiba and Hitachi devices is availability:smash:
What I dont understand is; if those devices are so good, why arent anyone making them:confused: :confused:
Steen:)
Ps. Russ, could wee see the latest schematic? |
|
|
| jacco vermeulen |
| quote: | Originally posted by steenoe
these old Toshiba |
Nikko Dalbani |
|
|
| BrianDonegan |
| I think I can get the Toshiba 2SK30A for $2.78 each. No sure how many though. Interested? |
|
|
|
