RE:Bias circuit pot and resistor changes
Hi,
I can't see why it should be a problem, just make sure that pin 1 is not used as a solder support inside the amp.
Expect the EL34s to be less powerful than the 8417s though.
I know the name AMC as a manufacturer of Hi-Fi amps ( some ex-NAD engineer founded it I think).
International? Dunno. National I do know.
Cheers,
Hi,
I can't see why it should be a problem, just make sure that pin 1 is not used as a solder support inside the amp.
Expect the EL34s to be less powerful than the 8417s though.
I know the name AMC as a manufacturer of Hi-Fi amps ( some ex-NAD engineer founded it I think).
International? Dunno. National I do know.
Cheers,
Hi Frank
On the base of the tube socket(8417/6550/KT88) pin 8 on both sockets I believe is the cathode. Pin 8 on both output tubes are connected and they go to ground. Pin 1 on the tube sockets is left unconnected.
On a 6550 tube inside, the cathode is connected to the Grid#3. I cannot find a pin out for a 8417 or a KT88 tube.
On a EL34 pin 8 the cathode is not connected to the grid #3.
I made the assumption that pin number 1 on the El34 could be connected to pin 8 and it would be the same as a 6550 connection wise.
The Quickie schematic doesn't show any connection from the cathode to the grid number 3 on the diagram showing the 8417 tube.
I connected pin 1 to pin 8 on the tube bases and tried all four tubes and it works. I wanted to be 100% sure so I thought I would check with you before I ran it for any length of time or damaged something.
As usual any help would be appreciated.
Joe
On the base of the tube socket(8417/6550/KT88) pin 8 on both sockets I believe is the cathode. Pin 8 on both output tubes are connected and they go to ground. Pin 1 on the tube sockets is left unconnected.
On a 6550 tube inside, the cathode is connected to the Grid#3. I cannot find a pin out for a 8417 or a KT88 tube.
On a EL34 pin 8 the cathode is not connected to the grid #3.
I made the assumption that pin number 1 on the El34 could be connected to pin 8 and it would be the same as a 6550 connection wise.
The Quickie schematic doesn't show any connection from the cathode to the grid number 3 on the diagram showing the 8417 tube.
I connected pin 1 to pin 8 on the tube bases and tried all four tubes and it works. I wanted to be 100% sure so I thought I would check with you before I ran it for any length of time or damaged something.
As usual any help would be appreciated.
Joe
QUICKIES.
Hi Joe,
When I asked if anything was tied to pin #1 of the sockets you replied:
Since I can't see anything else but the cathode, pin #8, that could be going to ground I assumed pins 1 & 8 were tied together and led to ground.
If that is the case than there is nothing for you to do, the EL34s should work straight in, other than the biasing, that is.
However if they used pin #1 on the sockets as a support for a resistor or whatever then we need to know what and how.
BTW, 6550, KT88, KT90 share the same basing diagram.
The only difference for the EL34 is that no internal connection is made between the suppressor grid (g3) and the cathode, so this needs to be done externally by tieing pins 1&8 together.
If you need both diagrams, I'll e-mail them to you.
Cheers,
Hi Joe,
When I asked if anything was tied to pin #1 of the sockets you replied:
Since I can't see anything else but the cathode, pin #8, that could be going to ground I assumed pins 1 & 8 were tied together and led to ground.
If that is the case than there is nothing for you to do, the EL34s should work straight in, other than the biasing, that is.
However if they used pin #1 on the sockets as a support for a resistor or whatever then we need to know what and how.
BTW, 6550, KT88, KT90 share the same basing diagram.
The only difference for the EL34 is that no internal connection is made between the suppressor grid (g3) and the cathode, so this needs to be done externally by tieing pins 1&8 together.
If you need both diagrams, I'll e-mail them to you.
Cheers,
Frank
I replied that pin 1 was left unconnected. Pin 8 is connected to both cathodes and goes to ground.
I connected pin 1 which was blank to pin 8 which went to ground.
This should tie in the cathode with grid 3.
I'm very pleased with the sound of all the tubes. I feel the KT88's have a little more low end. The 6550's have a more musical midrange and high end. The EL34's have a very pleasing sound also, haven't spent much time listening to them. I was surprised with the 8417's they really sound sweet.
I am quite pleased. It works with all tubes, is stable and the bias is easily set after modification of the bias circuit.
Joe
I replied that pin 1 was left unconnected. Pin 8 is connected to both cathodes and goes to ground.
I connected pin 1 which was blank to pin 8 which went to ground.
This should tie in the cathode with grid 3.
I'm very pleased with the sound of all the tubes. I feel the KT88's have a little more low end. The 6550's have a more musical midrange and high end. The EL34's have a very pleasing sound also, haven't spent much time listening to them. I was surprised with the 8417's they really sound sweet.
I am quite pleased. It works with all tubes, is stable and the bias is easily set after modification of the bias circuit.
Joe
Bias settings?
There seems to be a difference between the bias label on the 8417 amp and what is posted on the Quicksilver web site. I think they posted 115MA and the amp is labeled 125MA. Someone posted earlier about the amps eating valves, could this be the reason?
Any suggested bias setting for using the EL34 tubes? I would think that they probably can't be run with as much bias but then I'm a beginner with tubes so I'm humble asking for advise here.
Joe
There seems to be a difference between the bias label on the 8417 amp and what is posted on the Quicksilver web site. I think they posted 115MA and the amp is labeled 125MA. Someone posted earlier about the amps eating valves, could this be the reason?
Any suggested bias setting for using the EL34 tubes? I would think that they probably can't be run with as much bias but then I'm a beginner with tubes so I'm humble asking for advise here.
Joe
Quickies.
Hi,
I'd suggest setting them for 100mA.
Let's not forget that the QS run in class A1, so the tubes conduct fully all the time, music or not.
I'll try to find the correct bias setting for the 8417s.
The 6L6 family should work also in case you want to drive yourself nuts experimenting.
Cheers,
EDIT: Guess what....the 8417s should also be biased for 100mA and that is what is says on the schematic and the datasheets.
No wonder they die in a hurry with 125 mA.
Hi,
I'd suggest setting them for 100mA.
Let's not forget that the QS run in class A1, so the tubes conduct fully all the time, music or not.
I'll try to find the correct bias setting for the 8417s.
The 6L6 family should work also in case you want to drive yourself nuts experimenting.
Cheers,
EDIT: Guess what....the 8417s should also be biased for 100mA and that is what is says on the schematic and the datasheets.
No wonder they die in a hurry with 125 mA.
Re: Quickies.
Hi all
Frank , are you really sure the Quickies run in class A all the way?
I never had the curves , but from memory my Quicksilvers
had a B+ of up towards 500V , and a standing current of 60mA per side,
the 120mA bias is for both valves, remember.
I actually used to set the bias for 100 Ma , that is 50 mA per side.
Cheers
fdegrove said:Hi,
Let's not forget that the QS run in class A1, so the tubes conduct fully all the time, music or not.
EDIT: Guess what....the 8417s should also be biased for 100mA and that is what is says on the schematic and the datasheets.
No wonder they die in a hurry with 125 mA.
Hi all
Frank , are you really sure the Quickies run in class A all the way?
I never had the curves , but from memory my Quicksilvers
had a B+ of up towards 500V , and a standing current of 60mA per side,
the 120mA bias is for both valves, remember.
I actually used to set the bias for 100 Ma , that is 50 mA per side.
Cheers
Re: Bias settings?
Greetings to everyone,
First time posting here as I understand there are two 8417 per monoblock so it's actually around 60mA per tube. Btw, I always thought the "eating of tubes" was refering to the 5AR4 tubes as mentioned in Uncle Ned's website. Seriously I've been using the Quicksilver 8417 for many years and none of my Philips 8417 tubes have died on me yet.
Cheers
burnedfingers said:
Greetings to everyone,
First time posting here as I understand there are two 8417 per monoblock so it's actually around 60mA per tube. Btw, I always thought the "eating of tubes" was refering to the 5AR4 tubes as mentioned in Uncle Ned's website. Seriously I've been using the Quicksilver 8417 for many years and none of my Philips 8417 tubes have died on me yet.
Cheers
CURVES.
Hi,
I close my eyes and I see exactly what is mine...nothing.
Joke aside, I found them here:
AUDIOMATICA
Enjoy,
Hi,
I close my eyes and I see exactly what is mine...nothing.
Joke aside, I found them here:
AUDIOMATICA
Enjoy,
Frank
That was a nice link. I didn't see the tube base for the 8417 tube. Do you happen to have a link to it?
I just added 5881's to the list of usable tubes. They actually sound really clean. Some day when I get a wild hair I will check the distortion just to see if there are differences between the tube types. You probably have already done this and know the answers.
The 5881 is the last tube that I'm trying as I have just about worn out the tube sockets.
Joe
That was a nice link. I didn't see the tube base for the 8417 tube. Do you happen to have a link to it?
I just added 5881's to the list of usable tubes. They actually sound really clean. Some day when I get a wild hair I will check the distortion just to see if there are differences between the tube types. You probably have already done this and know the answers.
The 5881 is the last tube that I'm trying as I have just about worn out the tube sockets.
Joe
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