Just wondering if there is any chance one or more of the following improvements to this debate could be introducted:
a) Shutting down the thread.
b) Removing the flamewar posts between Thorsten and Positron.
c) Positron and Thorsten taking their flamewar into private messages, rather than trying to discredit eachother in a public forum, in response to someone's cry for help.
d) Thorsten and Positron adding each other to their respective ignore lists.
e) Positron and Thorsten getting with the programme, and making constructive posts.
f) DVDHack starting a new thread on this.
For what it's worth, both of you have sensible stuff to add to this debate, and I've enjoyed reading the stuff you've not directed at each other. Just try to stay on track. Rather than "am not, are too", why not try to get to the bottom of "why is that so"?.
/me gets off his soapbox now.
a) Shutting down the thread.
b) Removing the flamewar posts between Thorsten and Positron.
c) Positron and Thorsten taking their flamewar into private messages, rather than trying to discredit eachother in a public forum, in response to someone's cry for help.
d) Thorsten and Positron adding each other to their respective ignore lists.
e) Positron and Thorsten getting with the programme, and making constructive posts.
f) DVDHack starting a new thread on this.
For what it's worth, both of you have sensible stuff to add to this debate, and I've enjoyed reading the stuff you've not directed at each other. Just try to stay on track. Rather than "am not, are too", why not try to get to the bottom of "why is that so"?.
/me gets off his soapbox now.
To get back on track then what do you guys think of the possibility of using battery power for B+.Of course the heavy current heaters will be from the mains.I guess you could make it work with about 38-40 small SLA batteries rated at 2AH. Since the current draw is not more a couple hundred ma this should provide 6-7 hours of operation.If you get a good deal on batteries maybe a total cost would be about 500-550 euro which is cheaper than some mains transformers plus some good chokes.Being a big fan of batteries I think this should sound awesome although a bit scary- I wouldn't like to accidentally short one of those. Of course some reasonable way to charge them would be necessary.
I think some people have tried it.
I think some people have tried it.
question for thorsten (and others)
I have built a KT88 se amp much like the SJS-design with a 1660 interstage and plitron (amplimo) OPT. I use the 12HG7 in triode mode as a driver and I like the result very much.
In my cellar is the 2C51, 5842 and 6S45. I also have the C3M, el84 and E810F which i can use as drivers. I like to experiment a bit with the drivertube and have the plan to change this amp in a 300B "killeramp" as soon as I have decided about the best sounding driver.
Is there a clear winner or do you have another special preference (based on experience).
ciao,
Jaap
I have built a KT88 se amp much like the SJS-design with a 1660 interstage and plitron (amplimo) OPT. I use the 12HG7 in triode mode as a driver and I like the result very much.
In my cellar is the 2C51, 5842 and 6S45. I also have the C3M, el84 and E810F which i can use as drivers. I like to experiment a bit with the drivertube and have the plan to change this amp in a 300B "killeramp" as soon as I have decided about the best sounding driver.
Is there a clear winner or do you have another special preference (based on experience).
ciao,
Jaap
Re: question for thorsten (and others)
Konnichiwa,
E810F as triode. Exceptional linearity at good swing with around 200V on the Anode and fairly low (< 20mA) Anode current, very neutral yet high gain and still affordable. Then 6S45 & 5842 at 10 - 15mA 170V or so (experiement). Scratch the 396/2C51 for driver duties.
The C3m & EL84 make excellent pentode drivers (the E810F too actually), for IT/Triode stages they are not much different to a 6SN7/5687 respectively due to low transconductance and don't sound as neutral as something with more Gm.
Sayonara
Konnichiwa,
Jaap said:
E810F as triode. Exceptional linearity at good swing with around 200V on the Anode and fairly low (< 20mA) Anode current, very neutral yet high gain and still affordable. Then 6S45 & 5842 at 10 - 15mA 170V or so (experiement). Scratch the 396/2C51 for driver duties.
The C3m & EL84 make excellent pentode drivers (the E810F too actually), for IT/Triode stages they are not much different to a 6SN7/5687 respectively due to low transconductance and don't sound as neutral as something with more Gm.
Sayonara
thanx
for the answer. 7788 will be the first tot try.
This remembered me to an old article in Sound Practices. I looked it up and it appeared to be in issue 15. It is a 7788 (=E810F) driving a parafeed VT52B.
If I will build a 300B version I will use the filament set up of thorstens design (chokes and current regulator). The Sound Practices design of mr. Sanguinetti uses a complicated schema for the filament of the 7788.
For those who have seen it (i have no scanner): is it useful ?
JH
for the answer. 7788 will be the first tot try.
This remembered me to an old article in Sound Practices. I looked it up and it appeared to be in issue 15. It is a 7788 (=E810F) driving a parafeed VT52B.
If I will build a 300B version I will use the filament set up of thorstens design (chokes and current regulator). The Sound Practices design of mr. Sanguinetti uses a complicated schema for the filament of the 7788.
For those who have seen it (i have no scanner): is it useful ?
JH
Re: thanx
Hi,
Checked it. Grego runs 190V/28mA, I like even a little less current, but seems we are in the same "ballpark". For the "Low distortion Driver Circuit" Freaks, grego measured 0.17% THD on the anode of the 7788 for what amounts to 35V RMS, nearly full power form a normal 300B (full power is at 50V RMS or 3db higher where the THD should be also around 3db higher and thus still < 0.25%).
Use one or the other. I prefer CLC filter with big choke and an added CMC Filter Choke plus some 22uF/63V Film Cap's to any active scheme I tried, active schemes also with CMC.
If you absolutely want to feed the driver valve DC, it will do okay as "symmetrical" supply. I found that AC on indirectly heated drivers rules okay and often sounds better than regulated DC, AS LONG as you make sure to list the heater a few volt above cathode potential. I usually use Peak Voltage of the AC * 4 as ballpark for the "lift" voltage. Doing so reverse-biases the parasitic heater/cathode diode and leaves only very few pf of capacitive coupling that usually do little harm with the 50/60Hz heater supply.
Sayonara
Hi,
Jaap said:
Checked it. Grego runs 190V/28mA, I like even a little less current, but seems we are in the same "ballpark". For the "Low distortion Driver Circuit" Freaks, grego measured 0.17% THD on the anode of the 7788 for what amounts to 35V RMS, nearly full power form a normal 300B (full power is at 50V RMS or 3db higher where the THD should be also around 3db higher and thus still < 0.25%).
Jaap said:
Use one or the other. I prefer CLC filter with big choke and an added CMC Filter Choke plus some 22uF/63V Film Cap's to any active scheme I tried, active schemes also with CMC.
Jaap said:
If you absolutely want to feed the driver valve DC, it will do okay as "symmetrical" supply. I found that AC on indirectly heated drivers rules okay and often sounds better than regulated DC, AS LONG as you make sure to list the heater a few volt above cathode potential. I usually use Peak Voltage of the AC * 4 as ballpark for the "lift" voltage. Doing so reverse-biases the parasitic heater/cathode diode and leaves only very few pf of capacitive coupling that usually do little harm with the 50/60Hz heater supply.
Sayonara
Konnichiwa,
If you can solve all the attendant problems it is the best solution bar non. For solid state DIY (or Pogee) Gear I am a great fan of Batteries as supply. Given the numbers required to power the HT of Valve Gear I have so far avoided that.
That strikes me as throwing away most of the advantage of having batteries. The heaters especially of a DH Valve are linked to teh audio path mand need to be grounded somewhere. So you track all the dirt you kept out of the HT supply back in via your heater supplies.
Yes, this will provide at 1/10 rated current draw (0.2A) around 4 Hours of operation before the +B beginns to sag very notably and 8 Hours at 1/20 rated current (0.1A), assuming the batteries are brand spanking new. Let them age and the play time reduces.
Also, avoid series charging if you want to get the maximum lifespan out of the batteries. Parallel charging is an option but precludes "play & charge" modes for "non-critical listening or when the Batteries go flat.
With solid state gear I found the best solution was to have one charger per battery, still manageble if your Amp rund of 6 Batteries (12V/6AH) and your CDP of 3 Batteries. Design the charger well and your "play & charge" mode sounds only marginally worse than full battery power. The required numbers dissuaded me from applying this approach to HT supplies though.
What I have been thinking abouth though for series charging was a clamp across each battery with a switchable treshold of 14.4V (Recharge low cycled battery) and 13.8V (Float/Trickle Charge) plus a single CCS supply switchable between trickle charging (I = 1/20 rated capacity), trickle charge & play (I = 1/20 rated capacity plus nominal amplifier current draw) and cycle charge (I appx. 1/3 rated capacity). The control logic is easy enough for that, but still, it has so far remained on the drawing board.
Don't mind me, but a prettyserious supply can be kitted out with hammond parts and generic parallel compensation "lightning" capacitors for less than that and you need to add your charging circuits to the above amounts. Even if you only use parallel charging and use relais to switch all the batteries between charge & play, suitable high current relais costa few Euro each and you need a truckload, added to the truckload of batteries.
I'd love to see someone make this though. If you are interested in my "electronic - plug, play, forget" ideas I'm happy to discuss the state of this off-line.
One commercial 300B SE Amp with Battery +B is this one BTW....
http://www.lothx.com/silbatone 300 sel power amplifier.htm
Sayonara
protos said:
If you can solve all the attendant problems it is the best solution bar non. For solid state DIY (or Pogee) Gear I am a great fan of Batteries as supply. Given the numbers required to power the HT of Valve Gear I have so far avoided that.
protos said:
That strikes me as throwing away most of the advantage of having batteries. The heaters especially of a DH Valve are linked to teh audio path mand need to be grounded somewhere. So you track all the dirt you kept out of the HT supply back in via your heater supplies.
protos said:
Yes, this will provide at 1/10 rated current draw (0.2A) around 4 Hours of operation before the +B beginns to sag very notably and 8 Hours at 1/20 rated current (0.1A), assuming the batteries are brand spanking new. Let them age and the play time reduces.
Also, avoid series charging if you want to get the maximum lifespan out of the batteries. Parallel charging is an option but precludes "play & charge" modes for "non-critical listening or when the Batteries go flat.
With solid state gear I found the best solution was to have one charger per battery, still manageble if your Amp rund of 6 Batteries (12V/6AH) and your CDP of 3 Batteries. Design the charger well and your "play & charge" mode sounds only marginally worse than full battery power. The required numbers dissuaded me from applying this approach to HT supplies though.
What I have been thinking abouth though for series charging was a clamp across each battery with a switchable treshold of 14.4V (Recharge low cycled battery) and 13.8V (Float/Trickle Charge) plus a single CCS supply switchable between trickle charging (I = 1/20 rated capacity), trickle charge & play (I = 1/20 rated capacity plus nominal amplifier current draw) and cycle charge (I appx. 1/3 rated capacity). The control logic is easy enough for that, but still, it has so far remained on the drawing board.
protos said:
Don't mind me, but a prettyserious supply can be kitted out with hammond parts and generic parallel compensation "lightning" capacitors for less than that and you need to add your charging circuits to the above amounts. Even if you only use parallel charging and use relais to switch all the batteries between charge & play, suitable high current relais costa few Euro each and you need a truckload, added to the truckload of batteries.
I'd love to see someone make this though. If you are interested in my "electronic - plug, play, forget" ideas I'm happy to discuss the state of this off-line.
One commercial 300B SE Amp with Battery +B is this one BTW....
http://www.lothx.com/silbatone 300 sel power amplifier.htm
Sayonara
I am currently using 4 batteries per channel and one charger per two batteries in series.This seems to work well if the batteries are always charging and discharging equally. I was wondering if one could get away with series charging of the total 40 batteries as long as they come from the same batch and are facing the same charge/discharge conditions.OK maybe not all 40 - perhaps one charger per 4 batteries as a reasonable compromise.That would mean 10 charging circuits which is doable. A nice pcb would help make it even simpler
A bit risky I agree and you will probably say "just suck it and see" if it works.
Your scheme/plan is interesting but of course will need a lot of work , part count etc.Why can't they make some high voltage batteries for a change ?
A bit risky I agree and you will probably say "just suck it and see" if it works.
Your scheme/plan is interesting but of course will need a lot of work , part count etc.Why can't they make some high voltage batteries for a change ?
Konnichiwa,
I had this running with three batteries per string (with power zenner clamp as well) and after about a year and a halve things where sufficiently all over the place to cause the stacks to go flat early. I changed over to seperate chargers per batteries and new bateries, last I heard was still going well strong > 2Years after that.
Hence I don't do it myself.
For the same reasons it is difficult to make a suitable stack. Each SLA Cell only has 2V. A 100V SLA Battery would have 100 Cells and all in series, with invariably differentail aging.... No doubt the problems can be controlled, but all that costs research and production investment and all that for a few 100 Crazy Audiophiles. Not bloody likely....
Now if one of us could find a military application neccesitating 100V or 50V rechargable batteries with high reliability we might get them as surplus in a few years or tens of years.... ;-)
Sayonara
protos said:
I had this running with three batteries per string (with power zenner clamp as well) and after about a year and a halve things where sufficiently all over the place to cause the stacks to go flat early. I changed over to seperate chargers per batteries and new bateries, last I heard was still going well strong > 2Years after that.
protos said:
Hence I don't do it myself.
protos said:
For the same reasons it is difficult to make a suitable stack. Each SLA Cell only has 2V. A 100V SLA Battery would have 100 Cells and all in series, with invariably differentail aging.... No doubt the problems can be controlled, but all that costs research and production investment and all that for a few 100 Crazy Audiophiles. Not bloody likely....
Now if one of us could find a military application neccesitating 100V or 50V rechargable batteries with high reliability we might get them as surplus in a few years or tens of years.... ;-)
Sayonara
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