This may help as a A2 driver:
http://www.pmillett.com/A2CF.html
https://www.ebay.co.uk/itm/166653910355
Search found 15710 matches
- Fri Mar 22, 2024 9:49 am
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 110
- Views: 9447
- Fri Mar 22, 2024 9:18 am
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 110
- Views: 9447
Re: 6550 SE Amplifier
Eric has cap coupled to the A2 output stage which is supposed to cause “blocking distortion” in A2 Yep, it is a bit ugly that output stage. No need for quotes around blocking distortion, its a real thing and it will happen in that amp. he has tried to avoid it by using as big a coupling cap as prac...
- Sat Mar 16, 2024 12:21 pm
- Forum: Solid State
- Topic: Germanium Amplifier
- Replies: 162
- Views: 81063
Re: Germanium Amplifier
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 -
- Fri Mar 15, 2024 6:46 pm
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 110
- Views: 9447
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: 159530
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: 159530
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: 602
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: 34
- Views: 782
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: 16439
- Views: 4666672
Re: Nothing In Particular
Works for me.
- Tue Mar 12, 2024 2:31 pm
- Forum: News
- Topic: Paul Messenger
- Replies: 2
- Views: 477
Re: Paul Messenger
Yep, a genuinely nice guy.
- Tue Mar 12, 2024 8:48 am
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 110
- Views: 9447
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: 110
- Views: 9447
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: 81063
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: 110
- Views: 9447
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: 110
- Views: 9447
Re: 6550 SE Amplifier
Just remember the max anode voltage (cold) of a ecc88 is 550v.