DAMMIT I hate not being able to edit stuff... I know it doesn't HAVE to be regulated, but will I be able to hear a difference with a gainclone and Insignia bookshelfs? Also should it go
source -> attenuator -> B1 -> gainclone
source -> B1 -> attenuator -> gainclone
For the attenuator I'll prob wire up a quick n dirty linear pot (50k) w/shunt resistor (7.5k)...but I'll eventually be using an Optivol which has an input impedance of 27k and likes a high load impedance (100k+). I don't really understand the whole input/output impedance issue tho, which is why I was wondering about how to configure the chain
Oh and I measured 330kohms from output ground to L+ and output ground to R+ on my source...is that something important in such a discussion?
source -> attenuator -> B1 -> gainclone
source -> B1 -> attenuator -> gainclone
For the attenuator I'll prob wire up a quick n dirty linear pot (50k) w/shunt resistor (7.5k)...but I'll eventually be using an Optivol which has an input impedance of 27k and likes a high load impedance (100k+). I don't really understand the whole input/output impedance issue tho, which is why I was wondering about how to configure the chain
Oh and I measured 330kohms from output ground to L+ and output ground to R+ on my source...is that something important in such a discussion?
The B1 after the attenuator is the correct arrangement.
You are using the B1 to lower the output impedance of the pot BEFORE sending the signal down the interconnect.
The 330k are output resistors that take any leakage current from the source to ground. A similar resistor fitted to the input of much equipment does the same thing. Although bad practice to hot plug interconnects we (all) do it occasionally and having zero DC at the ends of the RCAs before plugging helps prevent the big bang at the speakers. Once the interconnect is established the two high resistances have almost zero effect on transferring the signal.
Your source will see a load impedance of ~50k at very low volumes, 50k//7k5 at maximum volume and a range of impedances between these limits at intermediate volumes.
The B1 will see 12k5//7k5 as the maximum source impedance down to near zero ohms at minimum volume. The B1 should easily tolerate this.
However, the source might not like 50k//7k5 (~6k5) as a load.
Another B1 installed in the source equipment would be a solution. But it might not need this drastic action.
Your last post confirms you have advanced to "edit" status.
You are using the B1 to lower the output impedance of the pot BEFORE sending the signal down the interconnect.
The 330k are output resistors that take any leakage current from the source to ground. A similar resistor fitted to the input of much equipment does the same thing. Although bad practice to hot plug interconnects we (all) do it occasionally and having zero DC at the ends of the RCAs before plugging helps prevent the big bang at the speakers. Once the interconnect is established the two high resistances have almost zero effect on transferring the signal.
Your source will see a load impedance of ~50k at very low volumes, 50k//7k5 at maximum volume and a range of impedances between these limits at intermediate volumes.
The B1 will see 12k5//7k5 as the maximum source impedance down to near zero ohms at minimum volume. The B1 should easily tolerate this.
However, the source might not like 50k//7k5 (~6k5) as a load.
Another B1 installed in the source equipment would be a solution. But it might not need this drastic action.
Your last post confirms you have advanced to "edit" status.
Hi Pink,
Being an eternal beginner myself, I strongly recommend you to study the datasheets of the active parts of every project you embrace.
OT, but not too OT:
I have built this gainclone with regulated supplies (+/-29V) and it does not sound too bad at all
http://www.pinkfishmedia.net/forum/showthread.php?t=39306&highlight=powerreg
(it has the link to the Teddyreg included)
I later took the (+) output of the PowerReg to feed another single ended class A preamp (which will be changed to a B1), through a (+) TeddyReg. A regulated integrated chipamp. Something to consider...
I like things complicated...
Cheers,
M
Being an eternal beginner myself, I strongly recommend you to study the datasheets of the active parts of every project you embrace.
OT, but not too OT:
I have built this gainclone with regulated supplies (+/-29V) and it does not sound too bad at all
http://www.pinkfishmedia.net/forum/showthread.php?t=39306&highlight=powerreg
(it has the link to the Teddyreg included)
I later took the (+) output of the PowerReg to feed another single ended class A preamp (which will be changed to a B1), through a (+) TeddyReg. A regulated integrated chipamp. Something to consider...
I like things complicated...
Cheers,
M
Hello Everyone
I finished assembling my B1 PCB last night many thanks to Nelson Pass for the simple lay out and great pcb's. I put the pcb into a old Dynaco pass preamp chassis to get it working. Later on I will build something better for it along with the shuntreg that is in the NS10 thread. Well it sounds GREAT for something that has really no burn in time it not a s forward sounding as my tube preamp I will compare the two over the next few nights also the Dell laptop power supply works like a charm.
Cheers
Dave
I finished assembling my B1 PCB last night many thanks to Nelson Pass for the simple lay out and great pcb's. I put the pcb into a old Dynaco pass preamp chassis to get it working. Later on I will build something better for it along with the shuntreg that is in the NS10 thread. Well it sounds GREAT for something that has really no burn in time it not a s forward sounding as my tube preamp I will compare the two over the next few nights also the Dell laptop power supply works like a charm.
Cheers
Dave
I got my b1 boards in and am looking for a few more parts to complete the b1 buffer preamp.
Where can I find a decent case?
I found the knobs (226-2030-ND) KNOB CLR GLOSS.75"DIA .125"SHAFT
and the pots (KA2531S28-ND) POT 25K OHM 2W LOG TAPER on digikey.
(hope they'll do)
I'm still looking for c101, c201 - I've got 2uf auri caps but I guess I shouldn't sub those in for the 10uf Axon.
I'm also looking for power adapter (18v - 24) and the power input jack.
Any help is greatly appreciated.
Thanks,
JG
Where can I find a decent case?
I found the knobs (226-2030-ND) KNOB CLR GLOSS.75"DIA .125"SHAFT
and the pots (KA2531S28-ND) POT 25K OHM 2W LOG TAPER on digikey.
(hope they'll do)
I'm still looking for c101, c201 - I've got 2uf auri caps but I guess I shouldn't sub those in for the 10uf Axon.
I'm also looking for power adapter (18v - 24) and the power input jack.
Any help is greatly appreciated.
Thanks,
JG
Axon=Solen
I think Axon are the same as Solen fast caps (read something to this effect on the internet).
You can get Solen from them in Montreal or from PCX (partsconnexion) in Toronto. PCX is having a sale right now.
Sayal in north Scarboro has walwarts or you can just order one from digikey. Read back in the recent pages for an example
Happy Hunting!
I think Axon are the same as Solen fast caps (read something to this effect on the internet).
You can get Solen from them in Montreal or from PCX (partsconnexion) in Toronto. PCX is having a sale right now.
Sayal in north Scarboro has walwarts or you can just order one from digikey. Read back in the recent pages for an example
Happy Hunting!
Solen will work fine if you can't fine Axon I bought mine years ago at Parts Express but they don't carry then anymore. Michael Percy has both types. http://www.percyaudio.com/
Hi Uriah,
Yes, Clarity caps are good, especially SA series...for the money.
http://74.125.45.132/search?q=cache...aps&hl=es&ct=clnk&cd=1&gl=cl&client=firefox-a[/url]
A comparison of caps in loudspeaker filters, but the description fits what I hear in low V circuits...
Cheers,
M
Yes, Clarity caps are good, especially SA series...for the money.
http://74.125.45.132/search?q=cache...aps&hl=es&ct=clnk&cd=1&gl=cl&client=firefox-a[/url]
A comparison of caps in loudspeaker filters, but the description fits what I hear in low V circuits...
Cheers,
M
Hi Max,
Great site thanks so much. He does a great job reviewing so many caps. Hopefully he and I have similar ears.
I bought the PX series. Also got some cheapies for about .90 each that I want to try to see the difference. Bought some Wima 10uf and Vifa 10uf as well as some Axon 1uf, Wima 1uf, Vifa 1uf. I dont know if I will actually get through trying them all or not.
Uriah
Great site thanks so much. He does a great job reviewing so many caps. Hopefully he and I have similar ears.
I bought the PX series. Also got some cheapies for about .90 each that I want to try to see the difference. Bought some Wima 10uf and Vifa 10uf as well as some Axon 1uf, Wima 1uf, Vifa 1uf. I dont know if I will actually get through trying them all or not.
Uriah
udailey said:
Ya I saw that but I'm not confident building it with all the mods involved and the specially designed PS. I was wondering about using smaller caps cause I'm kinda broke right now and wanted to use Sonicaps
I think I'll just put it off for a little while longerand while we're on the topic of capacitor reviews, Max...
http://www.ecp.cc/cap-notes.html
http://www.humblehomemadehifi.com/Cap.html (didn't realize that's the one Max linked to already; something's weird with that link above)
http://www.vhaudio.com/21capacitorshootout.pdf
http://www.head-fi.org/forums/f21/orgy-capacitors-cap-thread-284863/
