845 power stage.
#121
Great, I hope you measured the voltage across the ballancing resistors first, or at least with the meter connected via clipleads
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
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pre65
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#122
Meter was attached to the HT terminal and earth via clip leads before the power was switched on.
No hands near at any time !!
Amp B seems to be 10v less HT than amp A. Is that usual ?
No hands near at any time !!
Amp B seems to be 10v less HT than amp A. Is that usual ?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#123
Just means the transformers are within about 1% of each other. Near enough for Jazz.Amp B seems to be 10v less HT than amp A. Is that usual ?
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
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pre65
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#124
The 300b part of the setup has now been rewired and all 3 parts of the amp are ready for final testing.
http://i111.photobucket.com/albums/n146 ... SETamp.jpg
I have to go out soon and i won't get back till early evening so it will be a "tonight" job now.
http://i111.photobucket.com/albums/n146 ... SETamp.jpg
I have to go out soon and i won't get back till early evening so it will be a "tonight" job now.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
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pre65
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#126
After i had got home,and had my pizza i set about the task of powering up the SET with my old MF MC2 speakers attached.
BUM-all i got was a buzz and no music.
Scratch head (got splinter
) and check things over without getting intimate with 950 V and then realise i had not earthed the neg speaker terminal.
Phew,is that all !
Powered them down and let them drain then attached a couple of clip leads for the speaker earths. Power up again,buzz is less prominent but still no music !!!!
More splinters and tentative probes with the multimeter showed everything to be as it should (in my umble opinion) so a few more splinters !
Then it struck me,what a prat i am (so IanM2 was right)--I had not switched the DAC for the CD player on.
I am so pleased with the sound,will report more later.
BUM-all i got was a buzz and no music.
Scratch head (got splinter
) and check things over without getting intimate with 950 V and then realise i had not earthed the neg speaker terminal.Phew,is that all !
Powered them down and let them drain then attached a couple of clip leads for the speaker earths. Power up again,buzz is less prominent but still no music !!!!
More splinters and tentative probes with the multimeter showed everything to be as it should (in my umble opinion) so a few more splinters !
Then it struck me,what a prat i am (so IanM2 was right)--I had not switched the DAC for the CD player on.
I am so pleased with the sound,will report more later.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
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pre65
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#127
I will just say that the MC2 speakers have never sounded so good !!
After this CD i will go onto the VoFos and report back.
Bloody marvelous,i cant thank Nick enough for his technical help and lending me the interstages.
And not forgetting Steve (shadow) Darren and Andrew I for their contributions as well.
After this CD i will go onto the VoFos and report back.
Bloody marvelous,i cant thank Nick enough for his technical help and lending me the interstages.
And not forgetting Steve (shadow) Darren and Andrew I for their contributions as well.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
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Cressy Snr
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#130
Thanks for the thanks Philip and well done.
I bet it kicks some serious butt too
Steve
I bet it kicks some serious butt too
Steve
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andrew Ivimey
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#131
Hooorah. Hooorah, Hooorah!
Order of the Boatanchor is needed!
break out the champagne - now it begins.
Order of the Boatanchor is needed!
break out the champagne - now it begins.
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pre65
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#132
Thanks guys !
Having listened to MC2,VoFos and KLS3 for brief periods tonight i have to say that 845 favours the MC2 and KLS3.
As my "want" was for an amp to make the KLS3 really "sing" i can only say that i have achieved that aim.
Although i have liked the KLS3 for many years this is the first amp to really do them justice.
More listening (much more
) to come.
Having listened to MC2,VoFos and KLS3 for brief periods tonight i have to say that 845 favours the MC2 and KLS3.
As my "want" was for an amp to make the KLS3 really "sing" i can only say that i have achieved that aim.
Although i have liked the KLS3 for many years this is the first amp to really do them justice.
More listening (much more
) to come.The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
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pre65
- Amstrad Tower of Power
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- Joined: Wed Aug 22, 2007 11:13 pm
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#133
I must attend to the hum issue tomorrow.
Although i have a DC filament supply i used two 50 ohm resistors and took the cathode resistors/cap feed from the centre.
I will try it without the 50 ohm resistors,or i still have a couple of hum pots to try.
Does it matter whether i take the cathode resistor feed from pos or neg side of the filament ?
Although i have a DC filament supply i used two 50 ohm resistors and took the cathode resistors/cap feed from the centre.
I will try it without the 50 ohm resistors,or i still have a couple of hum pots to try.
Does it matter whether i take the cathode resistor feed from pos or neg side of the filament ?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#134
Not much. Try connecting the 300b amp ground and the 845 ground together.Does it matter whether i take the cathode resistor feed from pos or neg side of the filament ?
Also try without the 300b connected and the interstage input shorted.
Also try shorting the interstage secondary as well, to see if the interstage is picking up hum from the power supply.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
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Dave the bass
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#135
Blimey! It works and yer still alive, yeah!
Well done Philip, a brave man indeed.
DTB
Well done Philip, a brave man indeed.
DTB
"The fat bourgeois and his doppelganger"