JH, the volume control is $25 US from 8audio.com. The switch quality is equal to the Connex switches on partsconnexion.com. I build a shunt with the Connex and its the same quality and contact pressure, for lack of a better term. I suppose one could do better, but...
I don't have the values for the ladder. There are spreadsheets out there and I have a few. PM me with your addy. I'll zip some up and email them to you. Requires Excel or OpenOffice.
The blue LEDs on the F6? They develop the voltage for the bias. The amp heats up nicely after playing all day and I mean all day. Never too much heat sink. I think I could build a 50w F5T v2 with them. I have a 5w SIT in the same case that was displaced by the F6. I have the F5T boards, just need a reason.
Vince
I don't have the values for the ladder. There are spreadsheets out there and I have a few. PM me with your addy. I'll zip some up and email them to you. Requires Excel or OpenOffice.
The blue LEDs on the F6? They develop the voltage for the bias. The amp heats up nicely after playing all day and I mean all day. Never too much heat sink. I think I could build a 50w F5T v2 with them. I have a 5w SIT in the same case that was displaced by the F6. I have the F5T boards, just need a reason.
Vince
Oh, forgot to mention - if you can get your hands on some reasonably priced Rhopoint 'Econister' resistors (8G16/8E16) to replace those 'naked' Vishays to get a somewhat 'more analogue' (or darker) sound with similar amount of detail - like the difference between Manganin resistors (Rhopoints) and Isotan resistors (Vishays, or TC2575, etc)
The prices from various suppliers is 'all over the place' but sometimes reasonable - directly from Rhopoint and you have to pay a small quantity handling fee, as usual - similar with Newark (not sure about Element 14, UK)
The prices from various suppliers is 'all over the place' but sometimes reasonable - directly from Rhopoint and you have to pay a small quantity handling fee, as usual - similar with Newark (not sure about Element 14, UK)
JH, this is the first I'm hearing of Rhopoint. I think the aim of the naked Vishay is no resistor influence on the sound . My friend would probably like the idea of tuning the sound with parts. I'm more into getting rid of as many parts as possible. I think the B1 comes close to taking the preamp out of the chain altogether, yet having controls. I'll tell you, I won't look at preamps the same after my recent experience.
We were thinking about replacing the 1% MF resistor with Vishay at the listening position he uses most.
That's out of my pay scale. I was thinking PRP resistors, but will also check out the Rhopoints.
Thanks for the tip.
Cheers!
Vince
We were thinking about replacing the 1% MF resistor with Vishay at the listening position he uses most.
That's out of my pay scale. I was thinking PRP resistors, but will also check out the Rhopoints.
Thanks for the tip.
Cheers!
Vince
Ah, 8audio.com, right - interesting line up of components and quite reasonable prices - will check them out in detail
I was thinking about building a couple of 10kR Antilog pot for Thorsten's 'Tone Control' circuit ( circuit asked for 11kR - fascinating circuit design) - can't get anything like this today regardless of quality - any help appreciated - have ordered the Tremaine/Teffeau attenuator book at Amazon - it's been many years since last looked at this
I suggest you do a bit of a search about using multiple TC2575s - I vaguely remember something about the 'sound seems to get a bit 'edgie' when more than one (or a couple) used' - never heard of anyone trying this -
I use the PRPs a lot and they seem pretty good to me too - the Rhopoints seem to be still quite expensive unless you can get a 'bulk order' together - I make my own with the Manganin resistance wire (reel from Russia - eBay) and when the right values, try to get about 10 at a time and it's a bit more reasonable.
I was thinking about building a couple of 10kR Antilog pot for Thorsten's 'Tone Control' circuit ( circuit asked for 11kR - fascinating circuit design) - can't get anything like this today regardless of quality - any help appreciated - have ordered the Tremaine/Teffeau attenuator book at Amazon - it's been many years since last looked at this
I suggest you do a bit of a search about using multiple TC2575s - I vaguely remember something about the 'sound seems to get a bit 'edgie' when more than one (or a couple) used' - never heard of anyone trying this -
I use the PRPs a lot and they seem pretty good to me too - the Rhopoints seem to be still quite expensive unless you can get a 'bulk order' together - I make my own with the Manganin resistance wire (reel from Russia - eBay) and when the right values, try to get about 10 at a time and it's a bit more reasonable.
Hello Uriah, good to hear from you
Yes, I found the Manganin wire to be pretty good and okay up to a couple of kR but a bit of a pain over that - I think there's only the 365R/metre available in small reels these days and the all the 'new manufactured wire' is quite expensive, hence the Rhopoints.
I finally got onto using the higher silver content solder for terminating the ends and easier to attach pins/wire now - that Isotan is still an 'uneasy' termination, so I use crimp and solder and so far, so good.
I tried the 'pure copper' resistors using that very thin enamelled copper and a nearly totally transparent sound but a real PIA to make - I think those Dave Slagle resistors in vacuum tubes are pure copper and I wonder what they sound like?
Organising myself to play with your Lighter Note as a 3 resistor attenuator (T pad) - it's going to be either quite interesting or a real waste of time!
Yes, I found the Manganin wire to be pretty good and okay up to a couple of kR but a bit of a pain over that - I think there's only the 365R/metre available in small reels these days and the all the 'new manufactured wire' is quite expensive, hence the Rhopoints.
I finally got onto using the higher silver content solder for terminating the ends and easier to attach pins/wire now - that Isotan is still an 'uneasy' termination, so I use crimp and solder and so far, so good.
I tried the 'pure copper' resistors using that very thin enamelled copper and a nearly totally transparent sound but a real PIA to make - I think those Dave Slagle resistors in vacuum tubes are pure copper and I wonder what they sound like?
Organising myself to play with your Lighter Note as a 3 resistor attenuator (T pad) - it's going to be either quite interesting or a real waste of time!
Could someone give me some advise on how to match the different input impedances of CD and Phono to the B1? The sound quality with the buffer for CD is great! However, the difference in volume and sound quality with the buffer for Phono is not that great. Phono without buffer is not a solution either since it sounds a bit thin and non-involving (too much gain without buffer). Should I go with two buffers, one per input with different resistance, one before and after potentiometer? Or is there a way to alter the input settings for source 1 and 2 on the B1? Thanks for your help from this non-techie
If by phono you mean a turntable/record player, then your missing the basics.
turntables require riaa equalization as well as pre amplification.
the B1 BUFFER will not do either.
You also have the issue of mm or mc cartridge and then also what the cartridges specs are as they are not all the same..
turntables require riaa equalization as well as pre amplification.
the B1 BUFFER will not do either.
You also have the issue of mm or mc cartridge and then also what the cartridges specs are as they are not all the same..
Could someone give me some advise on how to match the different input impedances of CD and Phono to the B1? The sound quality with the buffer for CD is great! However, the difference in volume and sound quality with the buffer for Phono is not that great. Phono without buffer is not a solution either since it sounds a bit thin and non-involving (too much gain without buffer). Should I go with two buffers, one per input with different resistance, one before and after potentiometer? Or is there a way to alter the input settings for source 1 and 2 on the B1? Thanks for your help from this non-techie
Do you have a phono stage?
2 solutions.
a.)
add a source resistor to the higher Idss jFET to reduce it's Id down to 8mA and then use this as the CCS
b.)
use the lower Idss as the CCS.
This then pulls the lower Id through the amp jFET and the result is a very small output offset.
This offset can be canceled by adding a source resistor to the amp jFET and tapping off the audio output below the added source resistor where it meets the drain of the CCS jFET. Look up the Dennis Feucht article on using jFETs for a Buffer.
http://wayback.archive.org/web/20120710055701/http://www.analogzone.com/col_01302004.pdf
Another D.Feucht article worth saving:
http://www.google.co.uk/url?sa=t&rc...NjddIAhVcIt1AzQ&bvm=bv.85464276,d.ZGU&cad=rja
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Could anyone tell me wat is it?
Tekdevice DC Coupled B1 FET Buffer Preamp Toshiba 2SK170 BL JFET | eBay
Looks very small and not so complex built like DCB1 from group buy.
I want some kind of pre/buffer to feed my Dynaco ST35.
Is it good buffer to cooperate wit tube power amp like Dynaco?
Tank you.
Tekdevice DC Coupled B1 FET Buffer Preamp Toshiba 2SK170 BL JFET | eBay
Looks very small and not so complex built like DCB1 from group buy.
I want some kind of pre/buffer to feed my Dynaco ST35.
Is it good buffer to cooperate wit tube power amp like Dynaco?
Tank you.
Yea I assumed its only buffer without PSU but whats other stuff DCB1 got for example?
Would it be theoretically good match for power amp like Dynaco?
Im using single potentiometer right now (Noble pot) but tested Dynaco with good active preamp and it was much better, lifelike, more space and airness.
I would like to try something different and maybe B1 would be good idea. Unfortunatley Im not good at electronics so looking for ready solution.
I would especially like to hear opinion is it good partener for Dynaco ST35 tube power amp as I heard its not always the best option for certain amplifiers. Could you confirm that?
Would it be theoretically good match for power amp like Dynaco?
Im using single potentiometer right now (Noble pot) but tested Dynaco with good active preamp and it was much better, lifelike, more space and airness.
I would like to try something different and maybe B1 would be good idea. Unfortunatley Im not good at electronics so looking for ready solution.
I would especially like to hear opinion is it good partener for Dynaco ST35 tube power amp as I heard its not always the best option for certain amplifiers. Could you confirm that?
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Hi all, I have been lurking for a while and have been building my combination B1/Leach Phono stage using the great advice found in this forum. Thank you to all and thank you Mr. Pass. I had the unit hooked up last night to my Rowland M1 amps (two of them running in bridged mono configuration) and my wife commented that she was hearing details that she never heard before - even thought they were coming from somewhere else in the house.
I had two sets of the leach phono boards for 38 years and never stuffed them - good thing as there are better components available now. I used half of each set and made the phono stage dual mono. Used film caps wherever possible along with WBT solder and good wire from navships on eBay. The sound of this phono stage running into Mr. Pass's excellent design is amazing.
I will try and post some pics when I figure out how - my first post
Regards, Craig
I had two sets of the leach phono boards for 38 years and never stuffed them - good thing as there are better components available now. I used half of each set and made the phono stage dual mono. Used film caps wherever possible along with WBT solder and good wire from navships on eBay. The sound of this phono stage running into Mr. Pass's excellent design is amazing.
I will try and post some pics when I figure out how - my first post
Regards, Craig