What I love about that circuit is how much you can see valve thinking. Its basically a valve amp circuit with lower voltages and transistors.Just for reference, it's pretty much based on this - the 'Burns Orbit', which was a guitar amp apparently - I think -
Search found 15693 matches
- Sat Mar 16, 2024 12:21 pm
- Forum: Solid State
- Topic: Germanium Amplifier
- Replies: 162
- Views: 79750
Re: Germanium Amplifier
- Fri Mar 15, 2024 6:46 pm
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 104
- Views: 8479
Re: 6550 SE Amplifier
I find in the absence of test kit, the clarity (or lack of) of the voice in this is a good measure.I dont hear any 2nd so maybe the ecc88 is cancelling the worst of it? Answeers on a postcard.
- Thu Mar 14, 2024 8:32 pm
- Forum: Assorted Stuff
- Topic: Road vehicle fires.
- Replies: 157
- Views: 113205
Re: Road vehicle fires.
The reality of search engine algorithms means that just linking to something from another site increases its score. Increasing its score increases it's perceived value. And so on.
- Thu Mar 14, 2024 3:13 pm
- Forum: Assorted Stuff
- Topic: Road vehicle fires.
- Replies: 157
- Views: 113205
Re: Road vehicle fires.
Not sure if it's facts or conspiracy but possibly worth a listen, it just seems to me a funny world when an edited royal photo can make headlines for days and these events are seemingly covered up rather quickly? Or, you know, its neither facts or conspiracy, just someone on YouTube finding he can ...
- Wed Mar 13, 2024 2:44 pm
- Forum: Beginners
- Topic: Pot Impedance
- Replies: 3
- Views: 278
Re: Pot Impedance
No, the only reason for 100k is if its driven by other valve kit, that source may have a high output impedance so 100k would work better. No reason why 10k won't be just fine assuming your sources is happy with that.
- Wed Mar 13, 2024 9:03 am
- Forum: Everyones Projects
- Topic: GM70 Monoblocks’
- Replies: 4
- Views: 275
Re: GM70 Monoblocks’
38W @ 0.03% THD, £5 + Heatsink and power supply.
Just saying
- Tue Mar 12, 2024 8:32 pm
- Forum: Assorted Stuff
- Topic: Nothing In Particular
- Replies: 16428
- Views: 4478246
Re: Nothing In Particular
Works for me.
- Tue Mar 12, 2024 2:31 pm
- Forum: News
- Topic: Paul Messenger
- Replies: 2
- Views: 402
Re: Paul Messenger
Yep, a genuinely nice guy.
- Tue Mar 12, 2024 8:48 am
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 104
- Views: 8479
Re: 6550 SE Amplifier
Even without the 1.414/0.9 = 1.57 excess voltage, I was thinking more about the cold start condition of the ECC88 that will see the entire B+ on its anode until it starts to pass current.
- Mon Mar 11, 2024 9:55 pm
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 104
- Views: 8479
Re: 6550 SE Amplifier
Would need at least a 5W zener, but yes I guess so. But remember Max, adding some solid state may cause all manner of demons to fly out :-). A potential divider before the first stage would do the job, a 88 doesn't need a 80k load resistor, especially if its got a choke in there as well. Or just lea...
- Mon Mar 11, 2024 9:48 pm
- Forum: Solid State
- Topic: Germanium Amplifier
- Replies: 162
- Views: 79750
Re: Germanium Amplifier
Just a couple of thought, you are never going to be able to use much in the way of negative feedback in that amp (at least by comparison with a modern direct coupled circuit. That interstage is going to add so much group delay and general phase shifting nastyness that the most you can manage is PP v...
- Mon Mar 11, 2024 9:56 am
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 104
- Views: 8479
Re: 6550 SE Amplifier
They are your valves, so up to you. I manually turn heater supplies up then b+. Two outputs on the variac, all heaters first, then b+. I always assume a unexpected short term power outage could happen, so I either make sure that the startup control is automatic, or not needed. The chokes arent inste...
- Mon Mar 11, 2024 9:07 am
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 104
- Views: 8479
Re: 6550 SE Amplifier
Just remember the max anode voltage (cold) of a ecc88 is 550v.
- Sun Mar 10, 2024 9:36 am
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 104
- Views: 8479
Re: 6550 SE Amplifier
can sit in an oil bath to exceed ratings. Exactly how much difference would that make? I would have expected that most of the heat from the anode was dissipated as IR (it being in a vacuum and all that) so how directly is the envelope temperature related to the max dissipation? I suppose it would a...
- Thu Mar 07, 2024 10:45 am
- Forum: News
- Topic: Paul Messenger
- Replies: 2
- Views: 402
Paul Messenger
Will be missed, One of the good ones.