Haha, been here? Weather's pretty warm and humid lately, considering that its December we're hoping for some cool air from china to blow in, but no go. Thanks for the tips
Hi all,
I couldn't get the amp6 kit to work and probably destory the amp chip in the process, but that was before I went to Boracay (nice long white sandy beach.... 😎 )
Finally got another kit working and had to order 2 extra chip from Jan.
I skip the board ps and use a 5A 12V smps instead.
I also did use the original output filter as I have much better caps and some coil laying around.
The sound is very good indeed, more detail then GC I have but a bit less musical.
I think a lot of tweak can be done to this kit, like use a large cap for the 2 power pin, replace the output filter caps, change the feedback resistors to better ones, and I think the two 5V supplies can be tweak too. I am thinking about disconnecting the built-in 5V out pin and supply my own low noise ps.
I couldn't get the amp6 kit to work and probably destory the amp chip in the process, but that was before I went to Boracay (nice long white sandy beach.... 😎 )
Finally got another kit working and had to order 2 extra chip from Jan.
I skip the board ps and use a 5A 12V smps instead.
I also did use the original output filter as I have much better caps and some coil laying around.
The sound is very good indeed, more detail then GC I have but a bit less musical.
I think a lot of tweak can be done to this kit, like use a large cap for the 2 power pin, replace the output filter caps, change the feedback resistors to better ones, and I think the two 5V supplies can be tweak too. I am thinking about disconnecting the built-in 5V out pin and supply my own low noise ps.
That concurs with my findings Chuck! But, with a valve-pre in front of the class-T amps, it's much more musical and you get the best of both worlds!
I was there in 1981!
Need a bit of help re PSU section of amp6. I'm planning on adding a 5watt 15volt zener diode across c1819, the last capacitor in the PSU section. I want to implement a second "regulation" just in case the voltage setting resistors go bonkers. Is this a good idea? What will the effect be if the voltage coming out of c1819 is greater than the 15v rating of the zener? Will it explode or will it just stop the passage of the voltage? I'm also planning on putting another zener of the same specs across the input and output section of the voltage regulator, is this a good idea? My third question is this, if the amp is in sleep mode, will it be destroyed if the voltage coming in is greater than 16v or will it only be adversely affected by the voltage overshoot if the amp is in working mode. Thanks for taking time on my queries.
I can't answer all your questions DOHbert but I have always been told that we should avoid (noisy) zeneers unless there is no alternative.
Adding them to a circuit when you don't strictly need them seems like folly to me! 😉
Adding them to a circuit when you don't strictly need them seems like folly to me! 😉
Well I decided to bite the bullet and order one of these! It should be a blast to build!
I've been looking over the instructions and they seem pretty clear... But I have two quick questions:
1) The kit comes with the magnet wire for (ugh!) winding the toroids, right?
2) Are people using a mains switch for this puppy, or the sleep switch, or both?
I've been looking over the instructions and they seem pretty clear... But I have two quick questions:
1) The kit comes with the magnet wire for (ugh!) winding the toroids, right?
2) Are people using a mains switch for this puppy, or the sleep switch, or both?
That's correct.
I think that it is a good idea to use both. You never know when you may need to remove the power quickly!
Ahhh! That is a very good point! Well dual switches it is.
Just ordered the associated components from Jameco, gah I can't wait to get started... The waiting is always the hardest part isn't it!
Just ordered the associated components from Jameco, gah I can't wait to get started... The waiting is always the hardest part isn't it!
Well my Amp 6 board is about half finished now. Unfortunately, I'll have to wait until spring-break to finish it off. (My iron is back in Oregon.)
Anyway, general observations about the construction thus far:
- The SMD diodes are a pain to solder! I'm sure people with more experience in SMD find them easy because they are fairly large... Despite this I found them rather aggrevating. (Until I thought of using a third-hand style clamp with a pair of tweezers to hold it steady).
- Winding the toroids is a lot easier than it initially looks. (Of course, the amp isn't finished yet so I may have made some kind of a horrifying error that will become apparent later) I found it a lot easier to wind the toroids from the center instead of starting from one side. The other thing I observed is that it is better to think about shaping the wire to the toroid instead of "winding" it.
- The board itself is very cramped in some places... though entirely do-able so long as you have a small tip on your iron. This wouldn't make a good first-timer project though!
- The instructions are not the best written in the world but are acceptable.
Anyway, I'm rather irritated that this project isn't finished... but working on both a new pair of desktop monitors (small FE127s with a sub) and the amp simply proved to be too much for me during my brief hiatus from grad school... Ah well!
So anyone else have new amp6 related developments?
Anyway, general observations about the construction thus far:
- The SMD diodes are a pain to solder! I'm sure people with more experience in SMD find them easy because they are fairly large... Despite this I found them rather aggrevating. (Until I thought of using a third-hand style clamp with a pair of tweezers to hold it steady).
- Winding the toroids is a lot easier than it initially looks. (Of course, the amp isn't finished yet so I may have made some kind of a horrifying error that will become apparent later) I found it a lot easier to wind the toroids from the center instead of starting from one side. The other thing I observed is that it is better to think about shaping the wire to the toroid instead of "winding" it.
- The board itself is very cramped in some places... though entirely do-able so long as you have a small tip on your iron. This wouldn't make a good first-timer project though!
- The instructions are not the best written in the world but are acceptable.
Anyway, I'm rather irritated that this project isn't finished... but working on both a new pair of desktop monitors (small FE127s with a sub) and the amp simply proved to be too much for me during my brief hiatus from grad school... Ah well!
So anyone else have new amp6 related developments?
Need to ask a few questions regarding the SMPS and the onboard regulated PSU network of the amp6. I'm planning on using my toshiba notebook smps adapter, its 15v 4amp. I was thinking of attaching the regulated 15v to the big capacitor before the voltage regulator so I'll still get 14.3 volts after regulation. I want to try this setup since the maximum power output of the adapter is 15v, thus, even if the onboard regulator or power adj resistors get screwed up, I won't fry my tripath chip, my questions are:
1) is it a good idea to attach the poweroutput from the smps to the big cap? Do I have to remove the rectifier diodes?
2) Would I still get the benefit of a SMPS even if I pass the power output to the voltage regulator onboard?
Thanks for taking time on my queries 🙂
1) is it a good idea to attach the poweroutput from the smps to the big cap? Do I have to remove the rectifier diodes?
2) Would I still get the benefit of a SMPS even if I pass the power output to the voltage regulator onboard?
Thanks for taking time on my queries 🙂
I have such config. A small toschiba laptop 15V SMPS feeding a 41Hz Amp3. I used an additional diode (6A) (rectifier) to prevent wrong polarity and to drop voltage to 14.6 volt (from 14.93 volt SMPS). After the diode there is a 4700uF cap with a bleeder resistor.
It works like a charm and the sound is excelent. I might build another conventional PSU with a 65VA 12Volt torroid and lot's of capacitance for a second Amp3 but I doubt if it will be better.
I,ve mine all wired up with silver cabling and had it reviewed by a friend with 300B tube amps and 96db efficient Horns. He was utterly impressed and his tubes only won by a hair.
PS. I have not experienced any power supply pumping or oscilation effects that are occasionally mentioned in some threads nor can I think of a reason why it should occur at all. I'm a ME however and not an EE so it's not in my line of business either.
It works like a charm and the sound is excelent. I might build another conventional PSU with a 65VA 12Volt torroid and lot's of capacitance for a second Amp3 but I doubt if it will be better.
I,ve mine all wired up with silver cabling and had it reviewed by a friend with 300B tube amps and 96db efficient Horns. He was utterly impressed and his tubes only won by a hair.
PS. I have not experienced any power supply pumping or oscilation effects that are occasionally mentioned in some threads nor can I think of a reason why it should occur at all. I'm a ME however and not an EE so it's not in my line of business either.
The AMP-6 is different to the AMP-3 in that it has an onboard regulator and that's why DOhbert was asking about using an SMPS wit hit!
Now, can anybody tell me why the red LED is lit on my AMP-6 when the power is turned on (but not in sleep mode)?
My AMP6 has the red led on as well. Unfortunately, the forum on 41hz.com is almost dead, Jan is not answering emails either. I asked him about missing schematics a two weeks ago and no reply so far.
Fortunately mine worked right away, needed a few hours of burn-in. The sound is very good in my opinion. First I fed signal from variable output of my CD, but found the sound rather blurr.
I did a comparison with power amps of HK AVR 430, using its PRE-OUTs for AMP6. AMP6 was a winner, much thicker and detailed sound. The AVR is rather dry. Nevertheless, for loud modern music AMP6 was lacking power when feeding my 91dB KEF Q7s. Looking for some sensitive DIY fullrange horns now 🙂
For power supply, I was comparing SLA battery 12V/7.2Ah, regulated PSU with LM338, and standard SMPS for PC (12V/15A nominal, actual voltage 11.8V). I found the battery sound most lively. I took some ammatuer spectrum measurements for unloaded, resistive load, and AMP6 load power sources (battery, LM338, unregulated PSU, SMPS). The page is in Czech, but filenames of the pictures are selfexplaining.
http://www.f-sport.cz/hifi/index.php?action=vthread&forum=8&topic=503&page=2
I am curious about Jan's AMP4 with the TK2050 chipset - still in preparation I guess.
Fortunately mine worked right away, needed a few hours of burn-in. The sound is very good in my opinion. First I fed signal from variable output of my CD, but found the sound rather blurr.
I did a comparison with power amps of HK AVR 430, using its PRE-OUTs for AMP6. AMP6 was a winner, much thicker and detailed sound. The AVR is rather dry. Nevertheless, for loud modern music AMP6 was lacking power when feeding my 91dB KEF Q7s. Looking for some sensitive DIY fullrange horns now 🙂
For power supply, I was comparing SLA battery 12V/7.2Ah, regulated PSU with LM338, and standard SMPS for PC (12V/15A nominal, actual voltage 11.8V). I found the battery sound most lively. I took some ammatuer spectrum measurements for unloaded, resistive load, and AMP6 load power sources (battery, LM338, unregulated PSU, SMPS). The page is in Czech, but filenames of the pictures are selfexplaining.
http://www.f-sport.cz/hifi/index.php?action=vthread&forum=8&topic=503&page=2
I am curious about Jan's AMP4 with the TK2050 chipset - still in preparation I guess.
Thanks phofman, I'll hook up my AMP-6 and give it a try. I'm a bit concerned about the 140mV DC offset on one channel (85 mV on the other) so it will be used in my test system rather than my main system.
😉
I know Jan is extremely busy but I feel the lack of support, either from him directly, or on the 41Hz forums will limit the amount of kits that they sell! 🙁
😉
I know Jan is extremely busy but I feel the lack of support, either from him directly, or on the 41Hz forums will limit the amount of kits that they sell! 🙁
D0Hbert said:
D0Hbert - the dropout voltage of the LT1084 (this is what comes with the AMP6 kit, correct?) is specified as 1.5V max, but will probably be around 1V with the low current draw of the AMP6. That means you need to have at least 15.3V at the input of the regulator to get 14.3V out, and should ideally have more like 16V at the input of the regulator. If the input voltage to regulator is less than the desired output voltage plus the dropout voltage then the regulator output voltage will most likely be lower than what you want it to be and it won't regulate as well (but it will still work). You could bypass the regulator and use a diode to drop the smps voltage a bit like indoubt did.
If the AC inputs to the bridge rectifier aren't connected to anything then you can just leave them in place if you decide to try using the smps.
Will you still get the "benefit" of the smps... you'd have to listen and compare to find out. Technically, most switching regulators have better transient regulation than linear regulators, and that's where I think the smps is of benefit because class d output stages draw rapid bursts of current. I've used a regulator similar to the LT1084 to power my AMP3's and have used both 16V laptop smps and linear supplies before the regulator. I found that the sound was similar but slighty harsher in the upper frequencies with the IBM smps (my scope showed that the smps had a bit more noise and very high frequency ripple than my linear supply). The bass also sounded slightly better with my linear supply, thus I prefer to use my linear supply over the smps. Other smps probably sound different since everyone reports good results with them. Take note that my unregulated linear supply used to feed the regulator is a 120VA 15VAC plitron with a 20000uF filtering cap in parallel with a 0.1uF polyrpo film cap and bleeder resistor. It's very stiff and rather overkill, but that's a good thing in my book 🙂
Nuuk - Can you trace out the connections involved with the red LED and draw up a little schematic? I'd like to help you guys out but don't have an AMP6 to look at.
Thanks Brian, I apprecaite the help. But I've put the little blighter in the case now and it would be quite a bit of work to take it out and identify what goes where.
I can confirm, like DOhbert, that this AMP-6 works, and works well. It sounds very good, similar in signature to the Charlize and Autocostruire 2020 amps, as you would expect. 😉
Help!!!
I'm currently finishing 3 AMP6 modules to be used in my active setup.
However I have spotted a problem when following the manual (V 1.0).
With the kit came 5 capacitors with the following specs: 0.1 uF RM 2.5 mm.
However for the amplifier 6 of these caps are needed: C16, C17, C20, C26, C50, C102.
Am I doing something wrong? The bag in which the caps came said that
5 caps where supplied, hence I don't think it was a simple mistake with packaging side.
I'm currently finishing 3 AMP6 modules to be used in my active setup.
However I have spotted a problem when following the manual (V 1.0).
With the kit came 5 capacitors with the following specs: 0.1 uF RM 2.5 mm.
However for the amplifier 6 of these caps are needed: C16, C17, C20, C26, C50, C102.
Am I doing something wrong? The bag in which the caps came said that
5 caps where supplied, hence I don't think it was a simple mistake with packaging side.
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