It's got to be worth trying and will no have AC ripple. People say a 1uF shunt capacitor across the batteries works well. Do you have everything you need to try this? The sound might be better in an unexpected way.
The ripple has the obvious sawtooth harmonics as problem number one and the regulator is a simple amplifier that has a sonic signature as problem number two.
The ripple has the obvious sawtooth harmonics as problem number one and the regulator is a simple amplifier that has a sonic signature as problem number two.
There are some interesting references to battery power already here in this thread but you probably need to use Google or your favourite search engine to find them among some 600 pages. Graham Maynard R.I.P, had some interesting comments to make on battery power and of course, he wrote a long article (hated by EEs!) about the development of his own JLH amplifier version, over several issues of Electronics & Wireless World magazine, about 16 years ago.
Also long ago, I tried the usual 24V supply using 2 x 12V car batteries. They were old batteries and needed lots of recharging before they were ready for use, which became annoying. I eventually changed to a capacitor multiplier power supply, which was also very quiet - in fact good enough to forget about the batteries in my estimation, unless perhaps, you habitually listen up close to the your speakers.
Things have changed with batteries in recent times. Now we have solar power that reverse feeds the AC mains grid, aided by lithium battery storage too. I haven't taken that up yet but there are surely lots of possibilities with modern storage batteries since they are now available at competitive cost. There's nothing wrong with using lead/acid storage batteries either but I would avoid locating them inside the home as the acid vapour is often noticeable, despite the improvements with modern tech.
Also long ago, I tried the usual 24V supply using 2 x 12V car batteries. They were old batteries and needed lots of recharging before they were ready for use, which became annoying. I eventually changed to a capacitor multiplier power supply, which was also very quiet - in fact good enough to forget about the batteries in my estimation, unless perhaps, you habitually listen up close to the your speakers.
Things have changed with batteries in recent times. Now we have solar power that reverse feeds the AC mains grid, aided by lithium battery storage too. I haven't taken that up yet but there are surely lots of possibilities with modern storage batteries since they are now available at competitive cost. There's nothing wrong with using lead/acid storage batteries either but I would avoid locating them inside the home as the acid vapour is often noticeable, despite the improvements with modern tech.
Well said Ian. There are no easy solutions. Mains power supplies for class AB can have advantages over accumulators as lead acid batteries were often called.
Nice to hear from you Ian. I had a vivid dream about a motorcycle that woke me up. It wasn't a heroic one. Like a Honda 400 twin. A CB 450 I would prefer. Australia is where motorcycles work. No need to go fast.
Nice to hear from you Ian. I had a vivid dream about a motorcycle that woke me up. It wasn't a heroic one. Like a Honda 400 twin. A CB 450 I would prefer. Australia is where motorcycles work. No need to go fast.
Please don't charge anything bigger that about a 7Ahr wet lead acid in the house (the size of the one in your alarm system): wet cells generate hydrogen.(Yes, you can work out what Ahr size is safe in your house if you understand the math
)VRLA a.k.a. gell batteries are much safer but more fragile and will still out-gas if abused.
I've not tried them for audio but LiFePO4 are my current favourite smallish* remote power supply, particularly as you can now buy them as drop-in replacements for conventional Pb batteries, complete with built-in battery management systems. Half the weight, twice the capacity and the price is dropping like a rock.
Jean Hiraga's "Le Monstre" 8W Class A design was specified to run off a pair of 12V batteries. Your favourite search engine will find this but an interesting place to start is this translation from l’Audiophile No. 29
*between the 1kVA and 10kVA mark. NiCad and VRLA still rule my world for big ones
Last edited:
Oddly enough, I never tried the capacitance multiplicator circuit.
maybe I should give it a try one day.
I know my favorite jlh so well that I will immediately hear the difference.
I'm just missing a BD140 to assemble the final Rod Elliott circuit.
opinions? you tried ?
PS: totally agree for charging a lead-acid battery in a house, never in an unventilated room, there is a risk of blast!
as for LiFePO4 batteries, I haven't found anything better until now.
I use it to make custom batteries for old motorbikes which require a large amperage at startup (guzzi, laverda, bmw, ducati etc etc)
maybe I should give it a try one day.
I know my favorite jlh so well that I will immediately hear the difference.
I'm just missing a BD140 to assemble the final Rod Elliott circuit.
opinions? you tried ?
PS: totally agree for charging a lead-acid battery in a house, never in an unventilated room, there is a risk of blast!
as for LiFePO4 batteries, I haven't found anything better until now.
I use it to make custom batteries for old motorbikes which require a large amperage at startup (guzzi, laverda, bmw, ducati etc etc)
Hi Ian, do you have a pointer to any of the Maynard articles, or even a more precise date. I haven't come across them and they sound interesting.
Thanks
Mike
Member
Joined 2009
Paid Member
Du Cat I... reminds me of that scene in Yes Man
Attachments
Ducati is one of the very few mathematically correct motorcycle. In the old days each one was unique. Strangely Ducati made these logical engines for years without great interest. Now there are many clones. Desmodromic valves are more or less a Ducati invention. Air desmodromic valves are used in formula one. A genius design.
One of the Denizens of Doom (anyone remember alt.motorcycles?) penned the following (more or less, the rhythm is not quite right :-( )
"Taglioni thought valve springs moronic
So he made his bikes desmodromic
Endowed with the gift
Of positive lift
His bikes were both fast and euphonic"
Unfortunately, Google search is now Officially Crap and thinks this verse does not exist (whereas it was used as a .sig by a number of prolific posters pre- and post- The September that Never Ended )
Last edited:
Try the references in this thread which is more contemporary with the EW article and follow-up posts by Graham. You can also search almost any copy of E&WW mag. and other old UK publications here: RADIO and BROADCAST HISTORY library with thousands of books and magazines. It's ironic to find this treasure trove of UK publications in the US but at least someone recognized the value of the articles and bothered to scan the magazines intact. Whilst Keith Snook's library at d.c. ~ daylight ltd - Analogue - Audio - Video - Electro-optic - Electronic Engineering support & Design is often helpful too, his coverage is rather sparse.
Graham's Ideas progressed from his GM design and culminated in his GEM amplifier design (not to be confused with Dadod's Gem design) which was presented here at DIYaudio. It's a further step beyond the basic JLH design and adds a little complexity which will probably deter some of our newbies and purists but many of us will just be reminded that that we've been over this before.
Last edited:
Ian that is a very interesting set of information. I can see this design is a passion of yours. JlH is a hero of mine. Someone brought a JLH class AB amplifier to compare with Naim. I instantly was impressed. So much energy and sparkle. likely a different approach. If so JLH was adaptable. That JLH was as good or better than nearly anything I ever heard. It had very modest transformers compared with some. For all that it was very dynamic and open sound stage.
My talking Ducati was to say we often share similar feelings for other engineering when our French brother is in lockdown. I imagine Australia is far away from that?
My talking Ducati was to say we often share similar feelings for other engineering when our French brother is in lockdown. I imagine Australia is far away from that?
Do you know why I love Ducati so much?
because they forced me to discover the bmw.
I have a friend who is a fan of Italian and we did a lot of traveling together, except that at each departure we had to share the tools and other spare parts.
I got tired of it, I looked for a cheap motorcycle with luggage to transport the equipment, I came across a bmw, now I have 7 or 8
because they forced me to discover the bmw.
I have a friend who is a fan of Italian and we did a lot of traveling together, except that at each departure we had to share the tools and other spare parts.
I got tired of it, I looked for a cheap motorcycle with luggage to transport the equipment, I came across a bmw, now I have 7 or 8
on the other hand, I prepare ducatis for race in the vintage category.
it's engine really need careful work on intake and exhaust frequencies.
I can see very different results on the same engine depending on how the mechanic / preparer worked on it.
6 years ago with my group of friends, we started manufacturing 100% of a series of 8,750 TT1 and 4 TTF1, only the engines come from parts donor (750 ss 89 to 95) and the results are very different depending on who chose what on the engine and how he implemented it.
some are still in carburetors, others have switched to double-rail injection, complete with piloted and programmable ignition with specific MAPs for each racing circuit.
ZERO breaks engine in 6 years and yet, some pass the 10000trs
it's engine really need careful work on intake and exhaust frequencies.
I can see very different results on the same engine depending on how the mechanic / preparer worked on it.
6 years ago with my group of friends, we started manufacturing 100% of a series of 8,750 TT1 and 4 TTF1, only the engines come from parts donor (750 ss 89 to 95) and the results are very different depending on who chose what on the engine and how he implemented it.
some are still in carburetors, others have switched to double-rail injection, complete with piloted and programmable ignition with specific MAPs for each racing circuit.
ZERO breaks engine in 6 years and yet, some pass the 10000trs
My Italian delivery driver was talking Ducati. I lent him my book. 20 years ago I could almost speak French. In two years I think I should visit the region almost called Britain.
Moto Guzzi a BMW fussion with Ducati. I saw the BMW factory in Berlin when with my guide Frank Schroeder another DIY Audio member.
Moto Guzzi a BMW fussion with Ducati. I saw the BMW factory in Berlin when with my guide Frank Schroeder another DIY Audio member.
My girlfriend if people of 60 are that speaks good French and Italian. I must try. I say two years as it might be that long. A BMW R80 perhaps? If so I must remember it's not a Triumph Tiger 750. I was told mine was the last genuine Triumph. It was owned briefly by a Mr Frost. Registration LFC 824N. I was a civilian motorcycle instructor with Aylesbury Police.
The way an engine works is like an amplifier. The vibrations start from the compression phase being different to the exhaust phase. A sine wave with one in four parts flat topped. The Vas has similar requirements as the the connecting rod and components.
The way an engine works is like an amplifier. The vibrations start from the compression phase being different to the exhaust phase. A sine wave with one in four parts flat topped. The Vas has similar requirements as the the connecting rod and components.