One thing about the SLA is that the voltage drops over a time unlike modern LI-ion or Li-Fe, and this high current from battery kind of scares me.But I would like to listen if I have a chance.
One link about battery for tube audio. Warning!
Chul
Many many years ago I use to race RC Cars. Those things would pull well over 15A under heavy acceleration.
If you do dual mono battery supplies. It shouldn't be an issue. So Li Ion is definitely ok.
I don't see too much problem with SLA either.
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Hi all,
I have the attached case ready, with Noctua fan of right size and heat sinks to go inside the square pipe. I used this pipe for F6 for some days and it was more than enough.
I have two power supplys that have two adjustable 30V 3A and in series can make two 60V 30A, just short of 3.2A. FETs are cominig soon from Mouser I am open to the suggestion of power supply.
I also have two 48V 16A SMPS which can be used with DC-DC converter that ci11 suggested? These can even go inside the pipe(120mmx120mm internal).
So help me try this amplifier cicruit with power supply idea.
BTW, I have limited experience with battery for audio and I felt the differences from SLA, Li-ion, and Li-Fe in FET preamp. I liked the SLA and got this feeling that 'why inefficient things normaly sound better?' One thing about the SLA is that the voltage drops over a time unlike modern LI-ion or Li-Fe, and this high current from battery kind of scares me.
One link about battery for tube audio. Warning!
Chul
NICE! Like the column! Where did you get the wheels, they are cool!
I had a Li-Ion in my office on a laptop. The flame is invisible because it's colorless. Burns very hot and damage a lot. SLA is much safer for an old guy like me.
Hi picoDumbs,
As far as the voltage and battery capacity is enough on calculation, we can do it I think. Maybe we can recharge them when we sleep, and use them OK. I once used battery for tube audio and there were always some concern in my mind.
If the capacity is plenty, I forgot to recharge them because you do not have to it everyday, and often you see the low voltage when you want to listen to music. This low voltage makes you think that the operating point is different and you are listening to different sound than yesterday, unless you are using voltage regulator with battery.
If the capacity is just enough for daily recharge, you need to do it everyday and recharging the battery becomes some kind of everyday homework. What is needed is auto recharge selector between listen-recharge. I did not do this way and I failed to have peace in my mind about the SLA battery voltage...
I also felt that even the big difference with battery, something like music 'flood' instead of flow, I missed the AC linear supply sometimes. Maybe my other system component is not good enough or battery sound is sometimes just too smooth, as if I was accustomed to the some noise from AC power supply, but how can I know?
But with the right solution, I'd love to try battery supply for this power amp. But for now maybe SMPS could help me taste the sound much sooner and cheaper...
Chul
Hi Jaco and Ci11,
Thanks, and the all the material of that case is from the surplus in my work place, including the wheel that can bear about 100Kg per one. What I bought for this project are the heat sinks and Noctua fan.
I watched the Nelson's presentation at the BAF many times already. Nelson and DIYers here are all making our life more enjoyable and better!
Cheers,
Chul
Thanks, and the all the material of that case is from the surplus in my work place, including the wheel that can bear about 100Kg per one. What I bought for this project are the heat sinks and Noctua fan.
I watched the Nelson's presentation at the BAF many times already. Nelson and DIYers here are all making our life more enjoyable and better!
Cheers,
Chul
Dear ZM - thanks for the reply. Am I sensing is that even the 5U is a stretch for the 200Wpc dissipation of this beast?
I have a quote from Austerlitz for the KS216 in a custom 500mm length (per channel) which would give a 30° rise dissipating 200W. Not inexpensive but that's probably a safer option.
sorry , brainfart on my side ...... I don't know why I had 300W diss. figure in mind , while typing that
so , just for remainder - 60V x 3A2 means 192W of heat
4U/400 will cover 200W (100W per side ) , being little hot but adequate
4U/500 will be better and adequate
5U/400 little worse (than 4U/500) but adequate
5U/500 certainly best
all that , having direct experience with 4U/400 and 4U/500
so , just for remainder - 60V x 3A2 means 192W of heat
4U/400 will cover 200W (100W per side ) , being little hot but adequate
4U/500 will be better and adequate
5U/400 little worse (than 4U/500) but adequate
5U/500 certainly best
all that , having direct experience with 4U/400 and 4U/500
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Thanks again, ZM. It is now ABUNDANTLY clear!!
I just measured and either of the 500 cases will be too long to fit where i need it to go. So that may only leave me with the KS216-500 vertical as a speaker stand, the complete idea of which has yet to be worked out...
What if I use 1:2 transformer?
I have with me a pair of Sowter 8920 transformers which are regarded as good one. Will this be OK in the circuit? A 1:2 ratio and 20dB gain of the cicuit maybe I can even try passive pre including B1?
Parts are coming in inclluding the DC DC converter that ci11 suggested. (9$ per piece!) It's about time for that metal work..
Chul
I have with me a pair of Sowter 8920 transformers which are regarded as good one. Will this be OK in the circuit? A 1:2 ratio and 20dB gain of the cicuit maybe I can even try passive pre including B1?
Parts are coming in inclluding the DC DC converter that ci11 suggested. (9$ per piece!) It's about time for that metal work..
Chul
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The 4U only comes in 300mm and 400mm, 500mm is only available in the 5u case.
Hello Mr. Chul - good going! I already have Jensen 1:1's but also plan to use my LDR-driven passive. Picture shows it with my passive speaker EQ.
Would you mind measuring the ripple voltage of your 48V SMPS alone then together with the Boost DC/DC converter in the chain so we can see the effect of the DC/DC converter, if there is any? Thank you.
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I've taken to calling the hockey puck amp "Big Zen" since that was a long-time wishlist item for me. Who's gonna be the first to build the balanced 200 watter?
Hello Michael,
First - thank you for all your efforts at live streaming at the BAF - it was great to see and hear (almost) in person what's going on. I appreciate it!
I have nearly all the parts to go, but want to finalize the heat sink and power supply designs based on papa's article (when he releases it) for a few more details.
So it looks like Mr. Chul may well be the first our of the gate!
Oo
That's a very good point - what we call schade feedback today is what what was already in use with the original zen amplifiers. R8 and r5 in the first of them. Noting also that the term predates transistors.
I've taken to calling the hockey puck amp "Big Zen" since that was a long-time wishlist item for me. Who's gonna be the first to build the balanced 200 watter?
That's a very good point - what we call schade feedback today is what what was already in use with the original zen amplifiers. R8 and r5 in the first of them. Noting also that the term predates transistors.
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