The amps are input sensitive but work well with a passive volume control (20k)
plus I still think the amp is the sum of the parts (power supply and power amp ) that together make it one of my favourite amplifiers also at the time this was the same conclusion of most of the HiFi magazines that I had
plus I still think the amp is the sum of the parts (power supply and power amp ) that together make it one of my favourite amplifiers also at the time this was the same conclusion of most of the HiFi magazines that I had
Hello
I can provide 2 power amp PCB's and 2 power supply PCB's (4 pcb's in total)
plus 10 of each hard to get transistors
10 - BF870
10 - VN1210m
10 - 2N5459
£100 plus postage (approx. £10 tracked in the UK)
payment via paypal
hope this helps
regards
I can provide 2 power amp PCB's and 2 power supply PCB's (4 pcb's in total)
plus 10 of each hard to get transistors
10 - BF870
10 - VN1210m
10 - 2N5459
£100 plus postage (approx. £10 tracked in the UK)
payment via paypal
hope this helps
regards
Heads up
If any other constructors would like a JLH Mosfet bare mini kit
please PM me
all the best
If any other constructors would like a JLH Mosfet bare mini kit
please PM me
all the best
I do have the official Hart construction manual but will need to get it scanned as I do not have a scanner at home
unless any forum members have a copy in pdf ? I would be grateful for this
best regards
unless any forum members have a copy in pdf ? I would be grateful for this
best regards
I have attached 3 pictures to help with component placement - the new PCB's are the the latest revision ones that Hart Kits supplied which are slightly different from the magazine version (ETI May 1989)
My Gold versions are the same but I removed the ground plain as only one wire earth link is required
My Gold versions are the same but I removed the ground plain as only one wire earth link is required
although i have built this amp, it has some odd design features, so i cannot recommend it as such.
Hello Didyman
I will send you some part numbers for the transformer that can be used for the power supply
plus when I get the revised construction manual (hart kits version) I will send this to you in a pdf format
regards
I will send you some part numbers for the transformer that can be used for the power supply
plus when I get the revised construction manual (hart kits version) I will send this to you in a pdf format
regards
Hello Didyman
Please let me know when the package arrives
any issues please pm me ..
all the best 👍
Please let me know when the package arrives
any issues please pm me ..
all the best 👍
Thank You, Jamesfeline. I will waiting for it. 🙂 By the way, I didn't find any info about speaker impedance: does the amplifier suitable for 4 Ohm speakers, or should the power supply be modified?
Also please note that the design is valid and the PCB's if built with care will work
I have made at least 6 of these amplifiers (mono block form) and they work
On the power amp try and match the small signal transistors the best you can for best results
I have made at least 6 of these amplifiers (mono block form) and they work
On the power amp try and match the small signal transistors the best you can for best results
Just wondered if any one has the original Hart construction manual scanned in a PDF format ?
I have a hard copy but not a scanned version ? if a member could send me a copy that would be greatly appreciated.
If not I will try and get my version scanned and uploaded at a later date
best regards
I have a hard copy but not a scanned version ? if a member could send me a copy that would be greatly appreciated.
If not I will try and get my version scanned and uploaded at a later date
best regards
Hello,
The JLH Mosfet was my first DIY amplifier. I built it from a Hart kit and was really impressed with it. I still have the amp and 2 construction manuals, a fairly basic one that I received with the kit which looks like it has been scanned/reprinted several times and another later example. I have attached the first page of the later manual. This manual runs to 27 pages. I am happy to scan it if this is what you are looking for?
Best wishes
David
The JLH Mosfet was my first DIY amplifier. I built it from a Hart kit and was really impressed with it. I still have the amp and 2 construction manuals, a fairly basic one that I received with the kit which looks like it has been scanned/reprinted several times and another later example. I have attached the first page of the later manual. This manual runs to 27 pages. I am happy to scan it if this is what you are looking for?
Best wishes
David