Search found 15705 matches

by Nick
Thu Mar 14, 2024 3:13 pm
Forum: Assorted Stuff
Topic: Road vehicle fires.
Replies: 157
Views: 154169

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 ...
by Nick
Wed Mar 13, 2024 2:44 pm
Forum: Beginners
Topic: Pot Impedance
Replies: 3
Views: 574

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.
by Nick
Wed Mar 13, 2024 9:03 am
Forum: Everyones Projects
Topic: GM70 Monoblocks’
Replies: 12
Views: 546

Re: GM70 Monoblocks’

Image

38W @ 0.03% THD, £5 + Heatsink and power supply.

Just saying :-)
by Nick
Tue Mar 12, 2024 8:32 pm
Forum: Assorted Stuff
Topic: Nothing In Particular
Replies: 16439
Views: 4636055

Re: Nothing In Particular

Works for me.
by Nick
Tue Mar 12, 2024 2:31 pm
Forum: News
Topic: Paul Messenger
Replies: 2
Views: 473

Re: Paul Messenger

Yep, a genuinely nice guy.
by Nick
Tue Mar 12, 2024 8:48 am
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 110
Views: 9391

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.
by Nick
Mon Mar 11, 2024 9:55 pm
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 110
Views: 9391

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...
by Nick
Mon Mar 11, 2024 9:48 pm
Forum: Solid State
Topic: Germanium Amplifier
Replies: 162
Views: 80916

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...
by Nick
Mon Mar 11, 2024 9:56 am
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 110
Views: 9391

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...
by Nick
Mon Mar 11, 2024 9:07 am
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 110
Views: 9391

Re: 6550 SE Amplifier

Just remember the max anode voltage (cold) of a ecc88 is 550v.
by Nick
Sun Mar 10, 2024 9:36 am
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 110
Views: 9391

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...
by Nick
Thu Mar 07, 2024 10:45 am
Forum: News
Topic: Paul Messenger
Replies: 2
Views: 473

Paul Messenger

Will be missed, One of the good ones.

by Nick
Thu Mar 07, 2024 10:24 am
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 110
Views: 9391

Re: 6550 SE Amplifier

Thorston always was one for his brand. And trying to add a bit of woo by claiming that electrons have no reality is typical of that. The Standard Model may have a view on that :-)

I am with him with the no such thing as ground though :-)
by Nick
Tue Mar 05, 2024 10:58 am
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 149
Views: 30965

Re: OK…so I’m on wi’ summat

I have to be careful here as I have gone over to the dark side now, but I think that the preference for small caps in valve amps has two attractions. First, as Paul mentioned, taking the LF down too far just highlights the lack of flux in the output transformer, Secondly, if you have solved the flux...
by Nick
Mon Mar 04, 2024 12:35 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 149
Views: 30965

Re: OK…so I’m on wi’ summat

Probably Dave or Paul Joppa referred to the fact that protecting the se transformer from too much bass results in better bass. I think the tank effect referred more to the parafeed cap resonating with the two inductors in parallel (choke load and parafeed transformer) so I suppose you see a resonan...