I updated and moved the manual. It's now found at the amplifier page.
There is a chapter about different output transistors. Comparing TO-264 vs. TO-3. No final conclusion yet, but I find the new flat devises better.
Please comment, Thanks
\Jens
There is a chapter about different output transistors. Comparing TO-264 vs. TO-3. No final conclusion yet, but I find the new flat devises better.
Please comment, Thanks
\Jens
Jens,
mind telling the viewers what parts you are using ?
Especially the emitter resistors i am curious about.
(i am using 0.22 btw, Mox, unless someone can advice me how to get MPC's or Isabellenhute PBH's in a 1150 mil spacing)
After regular J time, of course.
mind telling the viewers what parts you are using ?
Especially the emitter resistors i am curious about.
(i am using 0.22 btw, Mox, unless someone can advice me how to get MPC's or Isabellenhute PBH's in a 1150 mil spacing)
After regular J time, of course.
To all builders:
Change of value for R28 and R30, both must be 330 ohm.
This is only important if you run the amp above +-60V rails
The change is in the componentlist on the website now.
I am making a table with values for different rail voltages, it will be included in the manual that I'm working on.
Sorry for any trouble this may cause, I know that removing components from the PCB is hard work, so please be carefull when you perform the operation
\Jens
Change of value for R28 and R30, both must be 330 ohm.
This is only important if you run the amp above +-60V rails
The change is in the componentlist on the website now.
I am making a table with values for different rail voltages, it will be included in the manual that I'm working on.
Sorry for any trouble this may cause, I know that removing components from the PCB is hard work, so please be carefull when you perform the operation
\Jens
Hi Jacco,
Nope, my prototype is running at +-75V as we speak, but on a test supply.
I just made a calc that suggested that 330 ohm was better for higher voltages 😉
I'm waiting for my 1000 VA 2x55V AC trafor, when it arrives I will make a short circuit test at see what happens 😱
EDIT: Did you have a look at the new graphs I mailed you Jacco?
\Jens
Nope, my prototype is running at +-75V as we speak, but on a test supply.
I just made a calc that suggested that 330 ohm was better for higher voltages 😉
I'm waiting for my 1000 VA 2x55V AC trafor, when it arrives I will make a short circuit test at see what happens 😱
EDIT: Did you have a look at the new graphs I mailed you Jacco?
\Jens
BUMMER, Oh well, maybe next time 
I have read the manual revision, Jens.
I figured weekend is J&J time.
And i am not the other J !!!!!!!!!!
The load line for the MJ15003/15004 on the 3 device version does point out how little the powerhandling of a device is worth.
I chose 0.22 Ohm emitter resistors instead of the 0.47 Ohm, or the original 0.33.
So i have to change R28/R30 anyway to activate the protection gear.
Setting it around 25 amps per device.
I am going to use an intelligent protection circuit that will activate the output relays depending on the product of Vce value and output current, with a delay of 10 mS.
Within the 10 mS its up to the Leach driver protection
btw: did you get my skype messages ?
first time i tried it, maybe you could give a hint for a convenient skype talk time schedule
I have read the manual revision, Jens.
I figured weekend is J&J time.
And i am not the other J !!!!!!!!!!
The load line for the MJ15003/15004 on the 3 device version does point out how little the powerhandling of a device is worth.
I chose 0.22 Ohm emitter resistors instead of the 0.47 Ohm, or the original 0.33.
So i have to change R28/R30 anyway to activate the protection gear.
Setting it around 25 amps per device.
I am going to use an intelligent protection circuit that will activate the output relays depending on the product of Vce value and output current, with a delay of 10 mS.
Within the 10 mS its up to the Leach driver protection
btw: did you get my skype messages ?
first time i tried it, maybe you could give a hint for a convenient skype talk time schedule
Emitter resistors
The reason for using 0.47 ohm in stead of the original 0.33 is to get better current sharing between the output devises (and I could get the 0.47 ohm devises)
Jacco:
I'm online now
\Jens
The reason for using 0.47 ohm in stead of the original 0.33 is to get better current sharing between the output devises (and I could get the 0.47 ohm devises)
Jacco:
I'm online now
\Jens
Jens, You dont seem to suggest the use of two traffos and two discrete PSUs for the modules. Is using two traffos a waste of time and money?
I plan to use only one trafo and one railvoltage. You can improve effeciency by using lower rails for the output .
I have not tested this, so if you try it please tell us the result, as it might improve performance with a more "silent" supply for the input part of the amp.
At the moment I'm waiting for my trafo. I will post results when it arrives. This will test the amp at 75V rails.
I was hoping on some more response on the manual - there are some things that might make the TO-3 vs. TO-264 debate come to life again.
\Jens
I have not tested this, so if you try it please tell us the result, as it might improve performance with a more "silent" supply for the input part of the amp.
At the moment I'm waiting for my trafo. I will post results when it arrives. This will test the amp at 75V rails.
I was hoping on some more response on the manual - there are some things that might make the TO-3 vs. TO-264 debate come to life again.
\Jens
Villaw said:
Using 1 transformer is a waste of money.
Do as Jeff Rowland does, use no transformer, stick 12 LM3886 in a box and charge +$ 10.000 for it.
Oh, why does no one post a couple of those nice Leach manual soa graphs on this thread !
jacco vermeulen said:
... and when the LM3886 shorts, whoever touches the speaker cable will get a nice electrocution and die...
P.S. : Sometimes I was talking with product manager of Revox and he said to me, that they need " junge blut ". Young blood was coming and spirit of WS gone away 😉 . By RR is it probably the same 😀 , " young blood " is offten quite cynical 😉 and is looking only for money.
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