Now, I do have 8x MUR860s leftover from my Peter Daniel's Gainclone kit, but I am sure I've read that they're not much good for high current Class A amps as it's not rated high enough. Any opinions on that?
I believe Peter stated as much over on his GB thread for the F-5. I used his recommended MUR 3060 devices. Others I know used HEXFRED block devices, WAY less soldering and fitment, thats for sure. That said, thesse MUR 3060 are tuff.
Russellc
Rusellc,
there's nothing really wrong with your amp as it is - you did a nice job
It's just that using the shorter leads gives you the feeling that you did everything right
Much appreciated. But if they need to be shortened to decrease power supply impedance......maybe I should. Right now I dont seem to be able to power down!
Russellc
I used this Vishay in my F5
Digi-Key - 30EPH03PBF-ND (Manufacturer - 30EPH03PBF)
but it's not available right now.
Diodes seem to be more problematic when you're using a transformer with high leakage inductance -- in this case, the junction capacitance of the diode and the leakage inductance form a resonant circuit -- and the diode rings -- the energy can be rectified by the various PN junctions in the amplifier and causes "unexplained, explained offsets".
I use 600va 4x18v toroidal transformer for stereo F5.In the past i used chinese made metal 35A bridge diode.And recently i found a higher quality IRF brand 40A bridge diode.There has been a voltage increase about 1.5volts then.I thought that it will be better to use an ultra fast diode but now i am confused(I also do not know how to connect 3 leg ultra fast diode.I want to seperate the stereo channels.Some of the diodes are common cathode and some of them are common cathode.Should i use them as complemantaries?)
To confuse you even further :
http://www.hagtech.com/pdf/snubber.pdf
Patrick
PS.... BTW BYW99W-200 is obsolete. There is a more up to date part STTH6002C.
STMicroelectronics | High efficiency ultrafast diode - STTH6002C
http://www.hagtech.com/pdf/snubber.pdf
Patrick
PS.... BTW BYW99W-200 is obsolete. There is a more up to date part STTH6002C.
STMicroelectronics | High efficiency ultrafast diode - STTH6002C
Hardly a dummies guide to snubbing capacitors, that
I also wonder if there is any deleterious quality brought in by snubbers whilst resolving things, and also I wonder if they are really needed.
I am not a believer of snubbers either. Most of the times, capacitance is your enemy, not your friend.
Keep things lean, clean and simple.
Electrolastic,
The last paragraph of the above PDF from Mr. Hagerman explains why snubbers are beneficial to the PS. (power line buzz is one example)
A simple but clear program to play with is PSUD2. The ringing from closing diodes cannot be beneficial to the end product----> HQ sound. Snubbers are cheap and easy to implement into the PS. If you like things "Clean"? Start with the Power supply ripple, that's where everything starts, and builds from there, why add to it?
This is My Opinion only, from very limited experience with tube Preamps, it seemed to add another level of clarity to the sound quality. IMO YMMV.
Ron
The last paragraph of the above PDF from Mr. Hagerman explains why snubbers are beneficial to the PS. (power line buzz is one example)
A simple but clear program to play with is PSUD2. The ringing from closing diodes cannot be beneficial to the end product----> HQ sound. Snubbers are cheap and easy to implement into the PS. If you like things "Clean"? Start with the Power supply ripple, that's where everything starts, and builds from there, why add to it?
This is My Opinion only, from very limited experience with tube Preamps, it seemed to add another level of clarity to the sound quality. IMO YMMV.
Ron
Ron:
Thanks for your information and opinion.
There are 2 camps of people, one camp likes snubbers on every PS, the other removes snubbers when one sees them. There were a few times that I even removed snubbers from factory-made amplifiers, turner and CD players.
The tube amplifiers, which I am still listening to, use tube rectifiers, therefore there are no place for snubbers. However, I'd even seen people snub the PS choke.
Thanks for your information and opinion.
There are 2 camps of people, one camp likes snubbers on every PS, the other removes snubbers when one sees them. There were a few times that I even removed snubbers from factory-made amplifiers, turner and CD players.
The tube amplifiers, which I am still listening to, use tube rectifiers, therefore there are no place for snubbers. However, I'd even seen people snub the PS choke.
Thank you for accepting my input as intended and not taking offense. So easily done on forums, I, myself am guilty of misinterpreting good intentions.
LOL, I'm one of "those" people who has a "valve" (jk) rectifier and has snubberised my choke. Go figure! Hey, send me your "extra parts" and I'll graft them onto my PS. Ha, Ha Ha. To each his / her own.
Ron
LOL, I'm one of "those" people who has a "valve" (jk) rectifier and has snubberised my choke. Go figure! Hey, send me your "extra parts" and I'll graft them onto my PS. Ha, Ha Ha. To each his / her own.
Ron
Any news (experience) with the Mini F5?
I for myself, I am also planning a four channel Mini F5 to drive the mid- and highrange horns.
These are my speakers:
In the last days, I configured them with the original passive crossover to use later with my (full) F5 I plan to build in one Telewatt enclosure.
But I found that the passive crossover is pure horror for my taste with this speakers.
So, back to active crossover, the (full) stereo F5 will drive the four FW250 cabinets.
I will use the second Telewatt enclosure I own to build in four reduced voltage/bias F5's.
Today I found the suitable trannie for about 10$:
12-0-12 Volt
Iron-size 13.5 x 11 x 12.5 cm
Weight 11 kg
I dont know, how much VA it is good for, but I guess more than 500VA. For what was it used before?
The inrush current may be a problem that must be carefully handled to not blow the apartements 10A fuses
Franz
I for myself, I am also planning a four channel Mini F5 to drive the mid- and highrange horns.
These are my speakers:
An externally hosted image should be here but it was not working when we last tested it.
In the last days, I configured them with the original passive crossover to use later with my (full) F5 I plan to build in one Telewatt enclosure.
But I found that the passive crossover is pure horror for my taste with this speakers.
So, back to active crossover, the (full) stereo F5 will drive the four FW250 cabinets.
I will use the second Telewatt enclosure I own to build in four reduced voltage/bias F5's.
Today I found the suitable trannie for about 10$:
An externally hosted image should be here but it was not working when we last tested it.
12-0-12 Volt
Iron-size 13.5 x 11 x 12.5 cm
Weight 11 kg
I dont know, how much VA it is good for, but I guess more than 500VA. For what was it used before?
The inrush current may be a problem that must be carefully handled to not blow the apartements 10A fuses
Franz
Last edited:
Franz: that looks like the trannie I bought from NASA in Alabama about 3 years ago -- came with an anodizing power supply. (3 for $1). The inrush current is enormous.
hmmm, looks to me like maybe a 1kw trafo, and that would be like 40A each secondary, maybe in that area
if your mains are 2kw it shouldnt be any problem there
and IE cores are more human than toroids, with inrush current
maybe better use very strong supply bridge and caps
but it is a problem with the needed large fuse
probably minimum 10A fuses, with softstart
and that wont present any safety at all
complete meltdown in case of failure
but its all guessing
and quite honestly, I wouldnt use such huge trafo for low output and easy load
smaller might even sound better
actually we have a saying like better small and awake than big and lazy
thou, it could handle multiple balanced outputs
maybe its possible to use a vario trafo in front of it
just thoughts
nice speakers btw
if your mains are 2kw it shouldnt be any problem there
and IE cores are more human than toroids, with inrush current
maybe better use very strong supply bridge and caps
but it is a problem with the needed large fuse
probably minimum 10A fuses, with softstart
and that wont present any safety at all
complete meltdown in case of failure
but its all guessing
and quite honestly, I wouldnt use such huge trafo for low output and easy load
smaller might even sound better
actually we have a saying like better small and awake than big and lazy
thou, it could handle multiple balanced outputs
maybe its possible to use a vario trafo in front of it
just thoughts
nice speakers btw
Thank you for your thoughts.
Indeed, this is a problem, I was not aware. Meltdown could also mean fire...
And as we know, secondary fuses are increasing output impedance in a very unlinear way.
This reminds me on a story when I was working in the service departement from Studer professional Audio:
A customer from asia asked for the original swiss fuses (Studer had a period they used secondary fuses on every board), as the swiss fuses are sounding better than todays asian market products
Franz
