The big heatsinks i am suggesting is to face heavy duty work
Full power, distorted power of 10 percent.... continuous distorted power...playing already distorted masters, modern electronic music or Heavy metal distorted music.... two channels driven and using two huge transformers of 2 kilowatts each one of them....so.... the available power, when distorting, will be huge, will go to 1 kilowatt each channel (2 ohms)
And believe me or not, there are guys that does not perceive that as bad sound...they understand that sittuation as "loud sound"...some guys feels distortions as "crisp" sound because introduces harmonics and sound starts to have more "body".... seems more solid...i do think it is awfull, but i see that many guys does not mind... the ones loves distorted, already clipped guitar tones (already present in the audio source recording) do not mind...for them this is much more an effect than a defect.
For "normal", standard use... to average listeners.... the ones does not accept distortion, these 15 by 30 centimeters heatsinks (2 pieces of 15 by 15 attached together in the picture), to one channel, will be good enougth to operate at 8 ohms with continuous undistorted tones (250 watts RMS) and will be good also for musical 500 watts... seems the average is 250 watts and you have peaks that will reach 500 watts or more.... listening normal music, not modern electronic music.... a jazz music, a classical music for instance.
My suggestion to use 7 times this heatsink shown is to heavy duty.... two channels as i said...pumping horrible continuous distorted sound at 10 percent THD levels...two channels playing.... so... power transistor will survive to such kind of torture.
You do not need to do this way if your transformer is smaller....your power to each channel will be, let's say limited, by 50 percent (aprox.) of your transformer power....so, if you select two 600 to 700 watts transformers, then your avaiable power may be around 350 - 450 watts RMS to each channel and this heatsinks shown in the 3D picture will be good for 8 and for 4 ohms...and i do think this is the most rational use.... instead to push the unit to produce 2 kilowatts in stereo with 10 percent distortion (chip amplifiers uses 10 percent specification because people really goes to this level... average people... no audiophile people...less demanding people)
Please, watch the power specifications to 8 ohms and 4 ohms.... this gonna be the most used condition i suppose... watch the demand of transformer power, the continuous power and distortion levels.... your transformer power will be what will decide the power you will be able to put out from your amplifier...so.... take care about this decision and select heatsinks, rectifiers, electrolitic condenser bank.... all this in order to face your custom use...not to waste money buying giant transformers that will never be needed to your particular application.
So, select your power transformer in order to match your power needs...if you need 150 undistorted watts to each channel, if you do not tollerate distortion, then you will be running at this maximum power level...maybe to match your expensive speaker power ration, then select two 300 watts transformers or a single 600 watts transformer.... this will limit your power if you do not increase further entering distortion.... will protect and match your speaker and will save your money in heatsinks, rectifiers, electrolitic condensers, size of your case and transformer...will avoid to waste money and will save your speaker coil to be melted by a crazy kilowatt. sustained power.
Observe that your selection will save money a lot.... to 200 watts you will need 10 thousand plus 10 thousand microfarads to each channel.... two 5A bridge rectifiers will be good...heatsinks will not be that huge...transformer will not be that big too.
regards,
Carlos
Full power, distorted power of 10 percent.... continuous distorted power...playing already distorted masters, modern electronic music or Heavy metal distorted music.... two channels driven and using two huge transformers of 2 kilowatts each one of them....so.... the available power, when distorting, will be huge, will go to 1 kilowatt each channel (2 ohms)
And believe me or not, there are guys that does not perceive that as bad sound...they understand that sittuation as "loud sound"...some guys feels distortions as "crisp" sound because introduces harmonics and sound starts to have more "body".... seems more solid...i do think it is awfull, but i see that many guys does not mind... the ones loves distorted, already clipped guitar tones (already present in the audio source recording) do not mind...for them this is much more an effect than a defect.
For "normal", standard use... to average listeners.... the ones does not accept distortion, these 15 by 30 centimeters heatsinks (2 pieces of 15 by 15 attached together in the picture), to one channel, will be good enougth to operate at 8 ohms with continuous undistorted tones (250 watts RMS) and will be good also for musical 500 watts... seems the average is 250 watts and you have peaks that will reach 500 watts or more.... listening normal music, not modern electronic music.... a jazz music, a classical music for instance.
My suggestion to use 7 times this heatsink shown is to heavy duty.... two channels as i said...pumping horrible continuous distorted sound at 10 percent THD levels...two channels playing.... so... power transistor will survive to such kind of torture.
You do not need to do this way if your transformer is smaller....your power to each channel will be, let's say limited, by 50 percent (aprox.) of your transformer power....so, if you select two 600 to 700 watts transformers, then your avaiable power may be around 350 - 450 watts RMS to each channel and this heatsinks shown in the 3D picture will be good for 8 and for 4 ohms...and i do think this is the most rational use.... instead to push the unit to produce 2 kilowatts in stereo with 10 percent distortion (chip amplifiers uses 10 percent specification because people really goes to this level... average people... no audiophile people...less demanding people)
Please, watch the power specifications to 8 ohms and 4 ohms.... this gonna be the most used condition i suppose... watch the demand of transformer power, the continuous power and distortion levels.... your transformer power will be what will decide the power you will be able to put out from your amplifier...so.... take care about this decision and select heatsinks, rectifiers, electrolitic condenser bank.... all this in order to face your custom use...not to waste money buying giant transformers that will never be needed to your particular application.
So, select your power transformer in order to match your power needs...if you need 150 undistorted watts to each channel, if you do not tollerate distortion, then you will be running at this maximum power level...maybe to match your expensive speaker power ration, then select two 300 watts transformers or a single 600 watts transformer.... this will limit your power if you do not increase further entering distortion.... will protect and match your speaker and will save your money in heatsinks, rectifiers, electrolitic condensers, size of your case and transformer...will avoid to waste money and will save your speaker coil to be melted by a crazy kilowatt. sustained power.
Observe that your selection will save money a lot.... to 200 watts you will need 10 thousand plus 10 thousand microfarads to each channel.... two 5A bridge rectifiers will be good...heatsinks will not be that huge...transformer will not be that big too.
regards,
Carlos
Attachments
Last edited:
The distance of the transistors' holes from the edge of the board was carefully measured to ensure that the transistors will mount nicely to a vertical heatsink without bending the leads. No cutting will be necessary
This is very good Byron.... really very good.
about the transformer A Wayne... seems perfect to feed both channels, allowing you to have a very good power at 8/4 ohms with a very low distortion...if two of them will be more than perfect.
A good solution Wayne.... reducing transformer of cost and the use of something rational... as no one wants to listen distortions... these ones will be good to operate using 2 ohms loads having audio quality, or low distortion.
Your transformer choice is very good.
regards,
Carlos
about the transformer A Wayne... seems perfect to feed both channels, allowing you to have a very good power at 8/4 ohms with a very low distortion...if two of them will be more than perfect.
A good solution Wayne.... reducing transformer of cost and the use of something rational... as no one wants to listen distortions... these ones will be good to operate using 2 ohms loads having audio quality, or low distortion.
Your transformer choice is very good.
regards,
Carlos
Attachments
Last edited:
About lifted ground
Here you have some comments about:
About lifted ground to MKIII-Hx input. - YouTube
regards,
Carlos
Here you have some comments about:
About lifted ground to MKIII-Hx input. - YouTube
regards,
Carlos
The RCA input connector to the MKIII-Hx.... also you can use Canon plugs
Here you have a video link...down here:
RCA connector input for MKIII Hx - YouTube
And a picture attached,
regards,
Carlos
Here you have a video link...down here:
RCA connector input for MKIII Hx - YouTube
And a picture attached,
regards,
Carlos
Attachments
I found myself on the list in an earlier thread, so maybe more than one is possible. finding myself on the list was why I posted, fortunately we hadnt gotten to payment time! It had been a while, and I hadnt checked the thread in a while....good thing I did!
Russellc
BOARDS ARE HERE!
Boards have arrived and they are beautiful. There is one tiny mistake: a missing soldermask on one pad, but it should be easy to scrape off. Also, it's very close to a contiguous pad, so builders could just bend the lead over. Otherwise I was not able to find any flaws.
I'm super busy at work today, so PayPall invoices may not get sent out right away. I'll post photos tonight.
Boards have arrived and they are beautiful. There is one tiny mistake: a missing soldermask on one pad, but it should be easy to scrape off. Also, it's very close to a contiguous pad, so builders could just bend the lead over. Otherwise I was not able to find any flaws.
I'm super busy at work today, so PayPall invoices may not get sent out right away. I'll post photos tonight.
DX Blame MKIII Hx board photos
I've had more time to look over the boards. They are still beautiful, though I did find one other minor flaw. The holes for the 2.2ohm/1W resistors are not as big as I would like them to be. I had to force the leads of the resistors I have through the holes with a pair of needle-nosed pliers. These leads were a bit thicker because of the 1W rating. Also, note that Alex gave builders a choice of pairs of holes for the 0.47ohm/3W resistors. The thicker leads fit nicely into the "further apart" holes, but the "closer together" holes were too small. All the other components I tried fit perfectly, most importantly, all the transistors.
Oh . . . and the soldermask is on the wrong side.
just kidding
I've had more time to look over the boards. They are still beautiful, though I did find one other minor flaw. The holes for the 2.2ohm/1W resistors are not as big as I would like them to be. I had to force the leads of the resistors I have through the holes with a pair of needle-nosed pliers. These leads were a bit thicker because of the 1W rating. Also, note that Alex gave builders a choice of pairs of holes for the 0.47ohm/3W resistors. The thicker leads fit nicely into the "further apart" holes, but the "closer together" holes were too small. All the other components I tried fit perfectly, most importantly, all the transistors.
Oh . . . and the soldermask is on the wrong side.
just kidding
Attachments
Take your time matey, we're not in a rush...another tent and grill again
. . . and what in the heck does "tent and grill" mean? I guess it has something to do with waiting for something . . .
waiting your PM for how much I need to pay you
, anyways PCB's looks great, can't wait to have it in my hands.
Lovely boards..for sure they are.
Here a video about noise pickup in potentiomenters and star ground from Dx amplifiers:
Star ground and potentiometer noise pickup in Dx amplifiers - YouTube
regards,
Carlos
Here a video about noise pickup in potentiomenters and star ground from Dx amplifiers:
Star ground and potentiometer noise pickup in Dx amplifiers - YouTube
regards,
Carlos
How to install a volume control for a Dx amplifier
Here you have how to do it:
Volume control to Dx amplifiers - YouTube
regards,
Carlos
Here you have how to do it:
Volume control to Dx amplifiers - YouTube
regards,
Carlos
How to wire you home made MKIII-Hx power supply
Here you have instructions:
How to wire a supply for MKIII-Hx - YouTube
regards,
Carlos
Here you have instructions:
How to wire a supply for MKIII-Hx - YouTube
regards,
Carlos
I'm giving everyone 2 weeks
About half of the people who promised have paid. Thank you, and your boards have been shipped. I think it's fair to give people 2 weeks to pay up before I offer their boards to someone else. Two weeks may be too short, as this is vacation season, however, I wouldn't be surprised if several people never paid.
If you or someone you know wants some/more of these boards, it can't hurt to get on the wait list (currently with one person). After 2 weeks I'll go through the wait list, and if there are still boards left over, I'll sell them on a first-paid-first-shipped basis.
-Byron
About half of the people who promised have paid. Thank you, and your boards have been shipped. I think it's fair to give people 2 weeks to pay up before I offer their boards to someone else. Two weeks may be too short, as this is vacation season, however, I wouldn't be surprised if several people never paid.
If you or someone you know wants some/more of these boards, it can't hurt to get on the wait list (currently with one person). After 2 weeks I'll go through the wait list, and if there are still boards left over, I'll sell them on a first-paid-first-shipped basis.
-Byron
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.