Hi
I built a Leach amp some time ago, using Prof Leach's plans and PCB, but for various reasons it's not working as I'd like it to. I have the chassis, room for big heat sinks and a very robust 58-0-58 700VA power supply.
Should I re-build the original Leach amp or is there another amp I should consider?
I want to buy the PCBs rather than make my own. I want a high wattage amp, preferably >100W, as it will be driving speakers in a big room. (The long term plan is to actively biamp it to the woofers with a First Watt handling mid/highs, but this may never eventuate). For cost and time-saving, I'd like to re-use the same power supply and chassis.
Any suggestions greatly appreciated.
Thanks,
Joe
I built a Leach amp some time ago, using Prof Leach's plans and PCB, but for various reasons it's not working as I'd like it to. I have the chassis, room for big heat sinks and a very robust 58-0-58 700VA power supply.
Should I re-build the original Leach amp or is there another amp I should consider?
I want to buy the PCBs rather than make my own. I want a high wattage amp, preferably >100W, as it will be driving speakers in a big room. (The long term plan is to actively biamp it to the woofers with a First Watt handling mid/highs, but this may never eventuate). For cost and time-saving, I'd like to re-use the same power supply and chassis.
Any suggestions greatly appreciated.
Thanks,
Joe
Why not try getting the leach to work, it's a good proven amp, lots of documentation, many guys here who can help finding the fault.
Hi Joe,
Firstly, I do not want to steer you off course. You have not provided details as to your issues with the Leach design but that might be your best and cheapest option. Like was said above, we can try to help to get that going.
I can throw out there that myself and Bob Cordell have a couple of designs in the works and will eventually be offering blank pcb's for sale to the DIY community. I have done proto pcb's for both and Bob is graciously fine tuning the design, so there will be a follow on pcb revision for both designs. They are the BC-1 and DH-220C designs as in Bob revised power amp design book. The time frame is not known, so I do not want to stop you from using others work or getting your leach to work properly.
We are going to get DH-220C design done first since I have a few wanting those for their Hafler amp chassis upgrades. But they can be used in other chassis is the plan.
BC-1 proto bring up is complete, it performs quite well according to Bob's stringent testing. It will drive 4 and 2 ohm loads with a supply such as you have.
I know Valery and Jeff have some nice stuff available now too. Virtual Zero Audio Store
For me the biggest hurdle is the mechanical design and the chassis for which we would have to do some pcb revision of BC-1 for a DIYAudio or other chassis.
Rick
PS. I have a few BC-1 prototype pcbs left if you want them, enough for a 2 channel amp. It is a 2 pcb/ch setup. PM me if interested.
Firstly, I do not want to steer you off course. You have not provided details as to your issues with the Leach design but that might be your best and cheapest option. Like was said above, we can try to help to get that going.
I can throw out there that myself and Bob Cordell have a couple of designs in the works and will eventually be offering blank pcb's for sale to the DIY community. I have done proto pcb's for both and Bob is graciously fine tuning the design, so there will be a follow on pcb revision for both designs. They are the BC-1 and DH-220C designs as in Bob revised power amp design book. The time frame is not known, so I do not want to stop you from using others work or getting your leach to work properly.
We are going to get DH-220C design done first since I have a few wanting those for their Hafler amp chassis upgrades. But they can be used in other chassis is the plan.
BC-1 proto bring up is complete, it performs quite well according to Bob's stringent testing. It will drive 4 and 2 ohm loads with a supply such as you have.
I know Valery and Jeff have some nice stuff available now too. Virtual Zero Audio Store
For me the biggest hurdle is the mechanical design and the chassis for which we would have to do some pcb revision of BC-1 for a DIYAudio or other chassis.
Rick
PS. I have a few BC-1 prototype pcbs left if you want them, enough for a 2 channel amp. It is a 2 pcb/ch setup. PM me if interested.
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Thanks. Yes its a great amp and I had many happy hours listening to it. But for some reason it now keeps blowing fuses and a professional technician hasn't figured it out (yes, I know he/she should be able to).
I'm afraid I'm not an electronic circuit problem solver. I just want to listen to music rather than get bogged down in circuitry detail. I'd very much like to be able be to learn about that, but my life is just too busy. I'm able to follow simple instructions like put wire 'A' into hole 'B', which is how I built my amp.
It's also a long story, but I'm currently living in Connecticut (where I have access to a MakerSpace). I'd like to populate a PCB before moving back to NZ. My amp/chassis/power supply etc is still in NZ.
I am happy to rebuild new PCBs for the Leach amp, but I wanted to check what else was out there - the 'Honey Badger' amp looks very interesting, but if the DIYAudio vox pop has better suggestions then I'd be very grateful for them.
Regards,
Joe
i
DC Voltage Supply is too high.
use 40V - CT - 40V AC transformer
Leach amp is almost indestructible if u build it right and with genuine parts.
58VCT transformer is more suitable for 270 watt leach
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@geierasul: Nice idea to mount the power devices beneath the PCB. keeping the total footprint small. But won't it lead to mechanical stress at the devices when tightening them after soldering has been done?
Best regards!
Best regards!
You may have nailed it there - I did but the PCBs in a new chassis and had to increase the length of the wires to the output transistors, then it started blowing fuses when it had been working perfectly before. Thanks very much for your suggestion.
One of the reasons I'd like to rebuild my amp is to tidy everything up on the inside and not have such a bird's nest of wires.
Regards,
Joe
But why is that any different from mounting the above the board? And why not solder the devices after mounting them on the heatsink?
