If I change my amp from diode to tube how much of a voltage drop can I expect? What would be a good tube to use(I would like one to fit an octal base, Have an extra on the chasis)?
Thanks
Thanks
Voltage drop depends on the tube used. You could use an 83 mercury vapour tube since those have pretty much no drop, but I believe that it is a 4 pin tube. A 5U4 would have about a 15V drop, its also a common tube used and somewhat beefy; a close relative would be a 5AU4 which is just way beefier, its rarely used in mainstream amps so it would be a good choice, its also octal. A schem of the amp would help, also the current and voltages.
normal tube rects - depends on the amount of current drawn.
merc'd rects.. (83, etc) is ~15v through the whole range of current.
5U4 @ ~200mA is something like a 45v drop.
merc'd rects.. (83, etc) is ~15v through the whole range of current.
5U4 @ ~200mA is something like a 45v drop.
Mind that I've never seen a single merc toob rated for more than 5uF cap input. In other words, they require a choke input filter. You'll drop about 1.3 to 1.5 times the voltage as compared to a SS rectifier (with cap input) in doing so.
Tim
Tim
Thanks, gives me a place to start. I will be going with a choke setup I think. Any thoughts on the 5ar4?
Dampers
Unless you're going to use new production , 5AR4/GZ34 will be expensive . Dampers such as the 6D22 and PY500a/42EC4 are excellent , rugged and fairly inexpensive . I have been using PY500A for the past two years and they can take anything I can throw at them . Dampers offer a slow start , high current , low volt drop and can withstand cap input topology . Try using the 6D22 model on PSUD2 and you'll see what I mean 😉
316a
Tim Wyatt said:
Unless you're going to use new production , 5AR4/GZ34 will be expensive . Dampers such as the 6D22 and PY500a/42EC4 are excellent , rugged and fairly inexpensive . I have been using PY500A for the past two years and they can take anything I can throw at them . Dampers offer a slow start , high current , low volt drop and can withstand cap input topology . Try using the 6D22 model on PSUD2 and you'll see what I mean 😉
316a
PY500A
If you need some PY 500A or PY88 valves, I have a pile of the things, all NOS and nout to do with them!!
Make us an offer!!
If you need some PY 500A or PY88 valves, I have a pile of the things, all NOS and nout to do with them!!
Make us an offer!!
Damper diodes
Hi all,
I was thinking of starting a thread on some of the better damper diodes to use, but since it's been brought up here, I might as well piggy-back my question on it now:
Given the current price of good sounding GZ34's
; What are fellow DIYer's opinions of which types are the nicer sounding "TV Damper diodes" around to start playing with?
I guess it would convienient if they didn't use top-caps; but ultimately, I'm not really fussed about that. I'll do what it takes to get good quality.
(Addendum: At the moment, my anticipated application for them is for a balanced preamp curcuit.)
Hi all,
I was thinking of starting a thread on some of the better damper diodes to use, but since it's been brought up here, I might as well piggy-back my question on it now:
Given the current price of good sounding GZ34's
; What are fellow DIYer's opinions of which types are the nicer sounding "TV Damper diodes" around to start playing with? I guess it would convienient if they didn't use top-caps; but ultimately, I'm not really fussed about that. I'll do what it takes to get good quality.
(Addendum: At the moment, my anticipated application for them is for a balanced preamp curcuit.)
Thanks for not shooting me over my first post Colt45 😉Colt45 said:good sounding diodes eh?
ah.. i'll be nice this time.
I am aware that not everyone thinks that individual component types (let alone brand...) have sonic signiatures of their own. So rather than re-start a controversy that I'm sure has been had on these forums already in many guises; my 'plea' for assistance goes out to who have already had a play around with some of these already, and might be able to offer some reccomendations.
I've only used GZ34's in the past myself (and the odd GZ37), and unfortunately I ain't rich enough to afford buying handfuls of each type of available damper diode to try myself, so I thought I'd ask those who might have gone through this already.
cheers again.
OK. I will overlook the highjacking of my thread🙂 , Because I want to know about different diodes as well as an alternative. Like what diodes would give a decent "sag" sound?
Well I don't know whether they give decent sag🙂 but I'm using 6cj3 damper diodes in my 845 amp and they sound great.
I'm using 4 in a bridge to supply 1250v (you'll need 2 for full wave rectification) and they drop 25v. They also don't have a top cap to knock off unlike other damper diodes like the 6D22.
Crowthorne tubes have some 6dw4, which are similar to 6cj3, on their site
http://www.crowthornetubes.com/valoff~1.htm
for £3 each.
John
I'm using 4 in a bridge to supply 1250v (you'll need 2 for full wave rectification) and they drop 25v. They also don't have a top cap to knock off unlike other damper diodes like the 6D22.
Crowthorne tubes have some 6dw4, which are similar to 6cj3, on their site
http://www.crowthornetubes.com/valoff~1.htm
for £3 each.
John
Hexfreds for rectifiers
Would anyone who knows care to share their experience with HexFred diodes? I've seen the switching characteristics on a graph and they don't seem to share the same freaky switching noise that the other types have.
Thanks in advance.
Would anyone who knows care to share their experience with HexFred diodes? I've seen the switching characteristics on a graph and they don't seem to share the same freaky switching noise that the other types have.
Thanks in advance.
Hi,
I thought that "sag" sound was due from the PS running out of steam, not the diodes as such.
For audio use the Shottkys are much preferred.
Cheers, 😉
I thought that "sag" sound was due from the PS running out of steam, not the diodes as such.
For audio use the Shottkys are much preferred.
Cheers, 😉
Given my own request here I can't really help you regarding diodes; but I know that many like the GZ37 rectifier because of its 'warmth' (as compared to a similarly premium GZ34).Tim Wyatt said:
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