This morning I powered up the front end and adjusted the voltages across R5/6;fortunately no issues doing so.As I am running with +- 38V dc I am only getting 11.3V at the jfets[cascoded] Is there an optimum voltage for the jfets as 11.3 seems a bit low. I thought that if I parraled a second 10k resistor;having used Audiosan's formula on the bom I would then have about 16V;would this be better? Tia.
10V-12v is considered sweet spot, I thkn. You can increase if you like and it will not hurt anything. I am unsure how it might affect clipping at higher power levels. It would be something you haev to test.
Thanks Buzz if 10/12V is considered the sweet spot I'll leave it as is and see how things go.Waiting on my alluminium supplier to get in touch then I can get busy with some drilling.
I've been waiting for those for months. I got responses "in 2-3 weeks will be ready" when I asked, but those weeks lasted months. Looks like the cad designer disappeared - at least untill the day I was waiting - . Go for tea-bags, their all-in-one and of spectacular quality. Only better option I see, is to etch your own.
buzzforb. or anyone else for that matter. please keep the English simple 🙂
what are the pro and cons of high or low rail voltage.
I'm using same teabag boards as you, fully populated.
yet to decide cooling but might go exotic 🙂
yet to decide trafo
my caps are several 100v 47000 so.....
any toughs??
ps building 4 boards so stereo mono ... so on ...
what are the pro and cons of high or low rail voltage.
I'm using same teabag boards as you, fully populated.
yet to decide cooling but might go exotic 🙂
yet to decide trafo
my caps are several 100v 47000 so.....
any toughs??
ps building 4 boards so stereo mono ... so on ...
Higher rail voltaage means more power into higher ohmic load. For instance, for 100w into an 8 hom load, you will need about 40-42V rails. For a 4 ohm load, you will need only 32v rails. Large impedance loads need more voltage swing. Low impedance loads need more current capacity If you are wanting higher than 100W into 8 ohm load, then you really need to consider balanced(bridged) topology, as this doubles the power into double the load. For example, an amp that can do 50W into a 4 ohm load will be able to do 100W into an 8ohm load if using a balanced(bridged) topology.
A consideration that is often overlooked is heat. Even if you can dissipate a lot of heat, the fet is still generating a lot of heat,internally, before your cooling system takes it away, so life expectancy becomes an issue.
What is your speakers setup?
A consideration that is often overlooked is heat. Even if you can dissipate a lot of heat, the fet is still generating a lot of heat,internally, before your cooling system takes it away, so life expectancy becomes an issue.
What is your speakers setup?
its the one I use as a avatar. will upgrade it to 2x6,5. keep tweeter scan speak 9500. superb parts in 24db filter. active sub is long stoke peerless 10" ( will be other amps). in side of speaker.
https://www.dropbox.com/s/sfri0z1tqnxjz8v/560607_374859012544847_627221751_n.jpg
edit.
so think I'll go for one 32 and one 42v.. so that one can compare 🙂
https://www.dropbox.com/s/sfri0z1tqnxjz8v/560607_374859012544847_627221751_n.jpg
edit.
so think I'll go for one 32 and one 42v.. so that one can compare 🙂
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well... no. not at the moment. the build is a little like this, without the slave . HIFI4ALL Forum: Dynabel Super Exact
I belive the kits name was dynabel exact, but I tweaked them ten years now so...
but they'r already now hard to drive and adding another 6,5er...
http://seas.no/index.php?option=com_content&view=article&id=68&Itemid=92
I belive the kits name was dynabel exact, but I tweaked them ten years now so...
but they'r already now hard to drive and adding another 6,5er...
http://seas.no/index.php?option=com_content&view=article&id=68&Itemid=92
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Go for 32V(42V rails) secondary. It will get you the 100W Class A. Make sure you have adequate heatsinking. It would be nice if you could have monoblocks. If necessary, you can just lower bias slightly.
I had forgotten this detail, the toroidal it comes from Poland, and I have built PSU equal to the original scheme of NP F5T V2.
This scheme has no resistances of bleeding, What resistance and power put, 2.2K in each rail as in std F5, or 10K on each rail?
The PSU has 120.000uF + 120.000uF.
This scheme has no resistances of bleeding, What resistance and power put, 2.2K in each rail as in std F5, or 10K on each rail?
The PSU has 120.000uF + 120.000uF.
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Do not know these accounts!
I still have some leftover from 2.2 K. I'll try to see if they do not get very hot ...
What I am saying is that the natural draw of the bias of the amps will drain the caps pretty quickly with out any bleeder.
I realized, this PSU does not need the resistances of bleeding, because when connecting the channels themselves dissipate the tension, correct?
Today I did a test PSU will, turned on a 2 toroidal 12V without connecting channels, and capacitors were with 17V rail on each, still have stored ...
the bleeder resistors is good to have. in case the amp fails in any way. 2.2Kohm 3-5W is fine. you can use higher value such as 10Kohm also.
I'm planning on building a F5T also. Same as TC-Goh
http://www.diyaudio.com/forums/pass...-your-diy-pass-amplifier-153.html#post3334011
I thinking about using 4 of these in the powersupply
ALC10C333EF035 - BHC COMPONENTS - CAPACITOR, 33000UF, 35V | Farnell Nederland
and make a possibility to choose between CRC and CLC. Transformer will be a 2x24V 625VA or 800VA.
The combination of 4x 33.000 uF and transformer will be used for 2 channels. I'm planning on building 2 stereo amps for either bi amping or maybe bridging.
Question: will this power supply be enough?
http://www.diyaudio.com/forums/pass...-your-diy-pass-amplifier-153.html#post3334011
I thinking about using 4 of these in the powersupply
ALC10C333EF035 - BHC COMPONENTS - CAPACITOR, 33000UF, 35V | Farnell Nederland
and make a possibility to choose between CRC and CLC. Transformer will be a 2x24V 625VA or 800VA.
The combination of 4x 33.000 uF and transformer will be used for 2 channels. I'm planning on building 2 stereo amps for either bi amping or maybe bridging.
Question: will this power supply be enough?
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