London Power device for power scaling - Page 1
Forum section: electronics / projects

author: Planobilly
author_rank: Regular Contributor
timestamp: June 11, 2016, 01:32:20 pm
content: Hi,Has anyone here installed a London Power power scaling device?I have not spoken to the company yet or have any idea what the cost of there device is.Just would like to know if anyone has used it and if so what you think.Cheers,Billy

author: ConKbot
author_rank: Super Contributor
timestamp: June 11, 2016, 07:50:53 pm
content: Unfortunately audio topics around here usually, don't go that far around here. The Dunning–Kruger effect tends to run rampant in any thread involving audio equipment, so out on a thick skin and hopfully a few helpful people will have valuable advice. While my tube knowledge is very very limited, the London power kits do look interesting and seem to have some technical basis behind them.Though being a guitar/bass amp thing, hopefully it shuts down most the typical retorts the anti audio crowd comes in with.

author: Planobilly
author_rank: Regular Contributor
timestamp: June 12, 2016, 04:10:43 pm
content: My experience here on the site has been good no matter what the subject matter was.I find people here are good about answering my questions even when it is apparent I am not very knowledgeable in some cases . I mostly only work on music electronics so it is what it is.Cheers,Billy

author: Delta
author_rank: Super Contributor
timestamp: June 12, 2016, 05:46:17 pm
content: What exactly does it claim to do?As far as I know, it simply isn't possible to get the same tone across all volume levels with a valve (toob) amp, as so much of the tone comes from overdriving the power stage. Even with an adjustable attenuator (is that was this is?), it will affect how the speaker load interacts with the output stage...

author: john_p_wi
author_rank: Regular Contributor
timestamp: June 14, 2016, 01:57:45 am
content: They work well, Kevin is the pioneer of power scaling for guitar amps. I've been a customer of his for nearly 20 years and a power scaling user for the last 10 or so. Power scaling definitely knocks off the edge and maintains the tone reasonably well, of course when the speaker is not pushing air, nothing sounds the same. You must control the signal drive levels, maintain proper grounding and preamp voltages too if you only scale the power amp.

author: retrolefty
author_rank: Super Contributor
timestamp: June 14, 2016, 02:09:11 am
content: Quote from: ConKbot on June 11, 2016, 07:50:53 pmLittle anti audio post around here, mostly just when anti-science claims are made with no objective evidence.

author: Anks
author_rank: Frequent Contributor
timestamp: June 14, 2016, 08:40:47 am
content: What it is doing is using a mosfet in the b+ line to scale it so that the tubes distort at lower volume. On fixed bias output amplifiers some consideration as to be taken into account so the bias is kept in a reasonable operating area.Nothing really to hard and schematics of amplifiers using this technique are about on the Internet.

author: Planobilly
author_rank: Regular Contributor
timestamp: June 16, 2016, 05:35:37 pm
content: Thanks guys for all the feedback.I communicated with Kevin the vendor, and got mostly positive feedback from others on this product. I think I will give it a try. At less than $100 there is little to lose.I have no illusion or expectation that this will make any amp sound the same as it is when turned up. This like most things in electronics it is a compromise. I just hope for a better sound than can be had using other methods.A Lamborghini Contach is a really cool car but not very usable to drive to the super market and yes one can reduce the horsepower. At that point it is not really a Lamborghini anymore...lolTo some extent we are trying to do the same thing to amps.There is a answer...Move to the country and turn the bloody thing up on 14...lolCheers,Billy

author: Delta
author_rank: Super Contributor
timestamp: June 16, 2016, 06:13:44 pm
content: Quote from: Planobilly on June 16, 2016, 05:35:37 pmI did pretty much just that, moved from a flat (apartment) to a detached house with no neighbours within 30m.I'd blown the 12" Celestion in my Marshall VS8080 with two weeks! ROCK ON!

author: The Soulman
author_rank: Super Contributor
timestamp: June 16, 2016, 09:29:20 pm
content: This one I really like:http://www.theboxofdoom.com/I´m not a guitarist but a live sound engineer and makes my life a whole lot easier..