We are offering free PCB for JLH 2005 class-A amplifier
Please get it here:
Free JLH-2005 Class-A Amplifier PCB
Each order is limited to 2pcs.
If you don't have the components please go with this cheap kit:
JLH-2005 Class-A Amplifier Kit for only $24
Please get it here:
Free JLH-2005 Class-A Amplifier PCB
Each order is limited to 2pcs.
If you don't have the components please go with this cheap kit:
JLH-2005 Class-A Amplifier Kit for only $24
Hi Oscar
Thanks for ordered. I saw 5 orders in the past hour.
Are you from Latvia? I'm not sure wether the flat rate shipping service is available for your country. I will ask the courier about it tomorrow.
Thanks for ordered. I saw 5 orders in the past hour.
Are you from Latvia? I'm not sure wether the flat rate shipping service is available for your country. I will ask the courier about it tomorrow.
First bath was sold out. The second batch will be made after the first design is tested. Keep on offering free PCB!
Happy with the testing reslut!
Today I'm sooooo happy with the testing result. After the following modifications of the original first design I posted:
1. VR1 changed to 100R
2. R13 changed to 10R
3. Q3 changed to BD139
The amplifier is working great! At the beginning the THD is 1% @1KHz/1W/8Ohm, pretty high for a class-A. I realize that Q1 and Q2 should be paired matched. Then I changed them with 2 pair matched transistors, the THD drops to 0.05%!
I also tried with some other transistors such as 2N3055, 2N3773 and finally 2SC5200. In my own opinion I like the sound of 2SC3280 most, high freq is very clear.
BD139 and BD140 works great in the testing. I think it's no need to worry about the high current. The don't have a heatsink and were slightly warm during working.
Hope your guys can also build a great amplifier when you receive my free PCBs.
Today I'm sooooo happy with the testing result. After the following modifications of the original first design I posted:
1. VR1 changed to 100R
2. R13 changed to 10R
3. Q3 changed to BD139
The amplifier is working great! At the beginning the THD is 1% @1KHz/1W/8Ohm, pretty high for a class-A. I realize that Q1 and Q2 should be paired matched. Then I changed them with 2 pair matched transistors, the THD drops to 0.05%!
I also tried with some other transistors such as 2N3055, 2N3773 and finally 2SC5200. In my own opinion I like the sound of 2SC3280 most, high freq is very clear.
BD139 and BD140 works great in the testing. I think it's no need to worry about the high current. The don't have a heatsink and were slightly warm during working.
Hope your guys can also build a great amplifier when you receive my free PCBs.
Attachments
Bug and testing report
Sorry for forgetting to mention a bug on the board. A trace is missing on the fist version, the 2 collectors of Q3 and Q8 are not connected. A flying wire can solve this easily
Tested THD with different transistors, testing condition is 1KHz, 6Ohm speaker, 1W output power
2N3055: 0.06%
MJ15003: 0.03%
2SC3280: 0.03%
MJ15003 and 2SC3280 should be better options for Q1 and Q2
Sorry for forgetting to mention a bug on the board. A trace is missing on the fist version, the 2 collectors of Q3 and Q8 are not connected. A flying wire can solve this easily
Tested THD with different transistors, testing condition is 1KHz, 6Ohm speaker, 1W output power
2N3055: 0.06%
MJ15003: 0.03%
2SC3280: 0.03%
MJ15003 and 2SC3280 should be better options for Q1 and Q2
Attachments
Hi Siliconray,
I am interested to get a kit
You need to buy 2 boards for a stereo set ?
When will your sell new batch of pcb ?
thanks
kp93300
I am interested to get a kit
You need to buy 2 boards for a stereo set ?
When will your sell new batch of pcb ?
thanks
kp93300
Yes you need to "buy" 2pcs for stereo. new batch will begin to sell at the beginning of Dec. Please feel free to order them here:
Free JLH-2005 Class-A Amplifier PCB
and get the full kit here:
JLH-2005 Class-A Amplifier Kit
Now there're more transistor options for the kit
Free JLH-2005 Class-A Amplifier PCB
and get the full kit here:
JLH-2005 Class-A Amplifier Kit
Now there're more transistor options for the kit
Hi deoN,
I just want to clarify the black PCB is free. the price is $0.01, I'm assuming it's equal to free because the system don't allow 0 as price.
I just want to clarify the black PCB is free. the price is $0.01, I'm assuming it's equal to free because the system don't allow 0 as price.
Hi
On your website, the US 4 price for the 2sc 3280 is for 2 pieces ?
Can you tell us the sound difference between the various types of Q1 and Q2 ?
thanks
kp93300
On your website, the US 4 price for the 2sc 3280 is for 2 pieces ?
Can you tell us the sound difference between the various types of Q1 and Q2 ?
thanks
kp93300
Hi Kp93300
the $4 is price different between 2sc3280 and 2N3055. I don't have golden ears so you can't believe my judgement. I just felt MJ15003 and 2SC3280 has more clear in high frequency. The measurement result shows that THD of MJ15003 and 2SC3280 is below 0.03% while 2N3055 is 0.05%.
the $4 is price different between 2sc3280 and 2N3055. I don't have golden ears so you can't believe my judgement. I just felt MJ15003 and 2SC3280 has more clear in high frequency. The measurement result shows that THD of MJ15003 and 2SC3280 is below 0.03% while 2N3055 is 0.05%.
Hi there,
I am very interested in the JLH amp kit that is being offered and have a few questions:
1) I need to buy two kits to make a stereo amp
2) how long will it take for shipping to Toronto, Canada if I choose the flat rate
3) you will take Paypal (I did not quite see it on your website) for payment
4) you will provide some support if needed (I am a newbie)
Thank you in advance for answering my questions.
Regards,
Lo_tse
I am very interested in the JLH amp kit that is being offered and have a few questions:
1) I need to buy two kits to make a stereo amp
2) how long will it take for shipping to Toronto, Canada if I choose the flat rate
3) you will take Paypal (I did not quite see it on your website) for payment
4) you will provide some support if needed (I am a newbie)
Thank you in advance for answering my questions.
Regards,
Lo_tse
Hello Lo
Yes you need 2 to build a stereo.
It takes about 2 weeks to Canada.
Just go ahead with checkout process you'll see paypal in the later steps.
Of course you can get support from me, thanks
Yes you need 2 to build a stereo.
It takes about 2 weeks to Canada.
Just go ahead with checkout process you'll see paypal in the later steps.
Of course you can get support from me, thanks
Hi Siliconray,
i order the kit from your web page or here ?
When will the new boards will be availabel for delivery ?
Have you corrected the board error in your new batch ?
thanks
kp93300
i order the kit from your web page or here ?
When will the new boards will be availabel for delivery ?
Have you corrected the board error in your new batch ?
thanks
kp93300
Hi Kp
Order them online please. New batch will have to wait for 1 week. old version can be shipped right now. It's not a big problem
Order them online please. New batch will have to wait for 1 week. old version can be shipped right now. It's not a big problem