arnoldc said:
nope;
as I said-that was a sin from youth-my variant of something (for me later) known as "RCA lookalike" or simpler- two triodes per channel with nfb EQ......
hehe
my LR riaa will be at least 10 times bigger
you can see at www how tiny line stage looks when I make them in this age...
regarding plans for LR riaa-seems that I found source for TFK EC8010;
just must check that source (I don't trust anymore to www stock lists)......when I lay my dirty hands on at least few pairs of these beasties,I'll start breadboarding
too much started projects in this moment
arnoldc said:
I'll go with 317 based CCS for filaments
regarding gas stabs- I have impression that 400V is lowest usable margin if 300V is working voltage
anyway-it's just me
Mark A. Gulbrandsen said:
Mark-mebbe is redundant to say this-but try to put those regs as close you can to 12B4 anodes
also-if something start to itchin' ya ,especially if you have golden ear and expensive CRO-try to connect 5 to 10 nf in parallel to each OD string (values are really from top of my head,but-smaller is better)
that way you will get rid of last trace of grain,if something is still left
There is a strike voltage i the OD3 specs, how would we take ito consideration this attribute in the design of the PSU?
Choky, can you share the reason why 400V to get margin for 300V B+. For 400V, I guess I will need a transformer voltage of about 350-0-350?
Choky, can you share the reason why 400V to get margin for 300V B+. For 400V, I guess I will need a transformer voltage of about 350-0-350?
Choky,
I will move all sections close together tonight. If I can find a chassis locally that fits everything I might just completely rebuild it into one box....
Mark
I will move all sections close together tonight. If I can find a chassis locally that fits everything I might just completely rebuild it into one box....
Mark
pengboon said:
study schmtc and imagine case when mains voltage is 10% down
yes-you need higher voltage than 280Vac
hehe-posting from Croatia,from my sister's place
choky said:
You mean the voltage at the plate of 0D3 must be 160V x 2 = 320V for it to ignite right? So even if mains voltage down 10%, it will still have sufficient voltage to work?
hi pengboon,
the VR150/0D3 has max voltage of 185V, strike voltage of 160V and operating voltage of 150V. Max of 40mA, min of 5mA to maintain regulation.
you will need two of these stacked, with individual small cap across each as choky said.
Here's how they're wired for my Gordon Rankin 807 amp before (but this one is VR105+VR150)
the VR150/0D3 has max voltage of 185V, strike voltage of 160V and operating voltage of 150V. Max of 40mA, min of 5mA to maintain regulation.
you will need two of these stacked, with individual small cap across each as choky said.
Here's how they're wired for my Gordon Rankin 807 amp before (but this one is VR105+VR150)
Attachments
arnoldc said:
OK, understood. I can use only 2 VR150s for both channels right, not necessary to have 4 VR150s?
You need 2 VR-150's for each channel. That also makes it dual mono from the regulators to the output and that is also better.
Mark
Mark
How abt headphones?
OK.
Can I use this linestage for headphones too? What modifications do I need if it's not possible by itself?
thanks for all your help!
OK.
Can I use this linestage for headphones too? What modifications do I need if it's not possible by itself?
thanks for all your help!
GG design
GG is good sonically, but not the best I heard. I built a simple one tube per channel Tung Sol 6P5GT linestage that is better sounding- more musical.
I used a Mullard EZ81 square getter rectifier to an LCLC PS filter to another LC per channel with plate chokes on each tube. Also, Vitimin Q PIO coupling caps. The plate chokes brought out the last bit of micro details without being edgy sounding.
Simple design cost less than 1/2 of the GG.
GG is good sonically, but not the best I heard. I built a simple one tube per channel Tung Sol 6P5GT linestage that is better sounding- more musical.
I used a Mullard EZ81 square getter rectifier to an LCLC PS filter to another LC per channel with plate chokes on each tube. Also, Vitimin Q PIO coupling caps. The plate chokes brought out the last bit of micro details without being edgy sounding.
Simple design cost less than 1/2 of the GG.
Well it is on.
Another Pass Shootout in Salt Lake City. We will be using Mark's 12b4 linestage with the gas shunt regulator, and also the solid state regulated power supplies, one for each channel, and comparing them both. Mark is trying to be open minded, but I sense he is leaning towards the shunt, and I, after spending another $40 on used tubes for the Eico, am definitely going to make my first build using one of these sweet solid state boards from Germany.
Lyndon
Another Pass Shootout in Salt Lake City. We will be using Mark's 12b4 linestage with the gas shunt regulator, and also the solid state regulated power supplies, one for each channel, and comparing them both. Mark is trying to be open minded, but I sense he is leaning towards the shunt, and I, after spending another $40 on used tubes for the Eico, am definitely going to make my first build using one of these sweet solid state boards from Germany.
Lyndon
I found someone who uses the 12B4 for headphones here:
http://www-personal.umich.edu/~monk/pre_amp.html
I'm probably going to use a HD600 or 650, so will this work without the OPT? or should i substitute another tube there?
http://www-personal.umich.edu/~monk/pre_amp.html
I'm probably going to use a HD600 or 650, so will this work without the OPT? or should i substitute another tube there?
Amperex,
I would like to hear your preamp.
Just a quick note here. Choky, I am sorry, but I couldn't discern any difference between the solid state regulated power supply vs. your
gas shunt one.
Mark differed, and felt the gas had a better sound. If looks count, yes, the purple glow off those things was pretty dramatic in a darkened room. But I think I am going ahead with the solid state when I build mine.
Lyndon
I would like to hear your preamp.
Just a quick note here. Choky, I am sorry, but I couldn't discern any difference between the solid state regulated power supply vs. your
gas shunt one.
Mark differed, and felt the gas had a better sound. If looks count, yes, the purple glow off those things was pretty dramatic in a darkened room. But I think I am going ahead with the solid state when I build mine.
Lyndon
Lyndon,
I had to share your views on the gas reg. Last week I rigged one of my PSU to feed stacked VR150+VR105 (same voltage as my MOSFET) and I cound not hear any difference. I have not put them up the scope tho. I have to admit though that I miss that purple glow.
Pengboon,
That entirely depends on your source if it has enough output to drive the 12B4. Also on the sensitivity and driveability of your cans.
I had to share your views on the gas reg. Last week I rigged one of my PSU to feed stacked VR150+VR105 (same voltage as my MOSFET) and I cound not hear any difference. I have not put them up the scope tho. I have to admit though that I miss that purple glow.
Pengboon,
That entirely depends on your source if it has enough output to drive the 12B4. Also on the sensitivity and driveability of your cans.