The design you linked to on DIY Audio Projects isn't a updated version of Le Monstre, it is a different design, though similar looking. While I cannot compare anything to Hiraga's designs having not built them, I can say that I have and enjoy a JLH. Mine is an original version but with different transistors; BC560 -> 2N3019 -> 2x MJ15003G's. The 15003's are a huge improvement over the 3055's in the original. I have PCB's pretty much loaded for the 2003 update with CCS's, but have been to lazy to finish them due to other projects. They are driving old Alnico magnet Fisher XP6's at the moment and are more than capable of pushing them to uncomfortable listening levels in my room. All in all I have been very pleased with the JLH, it was a good first amp project.
Cheers
James
Cheers
James
Thank you! I will certainly look into this. Do you recall how much it cost to have a pair made?
Blair
Yes,
I'm planning to use the MJ15003s as well. I have all the parts minus the trannys, power transistors and boards. I'll get them soon though.
Thanks for your impressions!
Blair
I don't recall but I believe they have standard pricing for eurocard (100x160mm) PCBs posted on their site.
I totally agree, I started with 2N3055s and upgraded later to MJ15003s and it was a very noticeable improvement.
I had trouble adjusting the bias current to be stable with the 2N3055s, perhaps because of gain mismatch between the transistors.
which heatsinks are you using for the MJs? I've been thinking about ordering those flanged Conrad ones. Any pointers to local suppliers?
I got lucky and won a lot of ten heatsinks on eBay. That is kind of what started this thing. I'll post a few pictures if I remember later. They are pretty nice!
Blair
Blair
Oh ok... that's great.
They maybe similar to the ones wakefield have.
http://www.wakefield.com/PDF/extruded_heat_sink.pdf
You may be able to get some thermal resistance numbers.
They maybe similar to the ones wakefield have.
http://www.wakefield.com/PDF/extruded_heat_sink.pdf
You may be able to get some thermal resistance numbers.
Hi All,
Just saw this thread,
A few things i would like to mention:
the original Le monstre is ~7-8W.
the original Le class A is around ~20-30W depending on supply.
the class A i built (in my avatar is ~50-60W)
the JLH 1996 version is ~15-30W depending on supply.
the original JLH "simple class A amplifier" is ~15W
I would suggest reading here for Hiraga and JLH schematics:
http://www.tcaas.btinternet.co.uk/
The PCB's for JLH 1996 version (the good one which is not cap coupled)
are available here: http://www.williamshart.com/
Happy building
-Dan
Just saw this thread,
A few things i would like to mention:
the original Le monstre is ~7-8W.
the original Le class A is around ~20-30W depending on supply.
the class A i built (in my avatar is ~50-60W)
the JLH 1996 version is ~15-30W depending on supply.
the original JLH "simple class A amplifier" is ~15W
I would suggest reading here for Hiraga and JLH schematics:
http://www.tcaas.btinternet.co.uk/
The PCB's for JLH 1996 version (the good one which is not cap coupled)
are available here: http://www.williamshart.com/
Happy building
-Dan
Hello Daniel,
Thank you for chiming in. I am unfamiliar with all the variations and that is why I think there are a few posts regarding my wattage figures. The high powered class A JLH I am considering on 23v rails makes 28w into 8 ohms and 56w into 4 ohms.
I'm glad you responded because your amplifier is what got this whole thing started for me. I like your design and was planning on building it instead, but I ended up getting a really good deal on heatsinks pretapped for TO-3 transistors.
Most of my speakers are relatively difficult loads to drive. Some of them dipping to two ohms at certain frequencies. I'd say 3-4 ohm nom. Impedance. This is why the high power JLH seemed attractive. I figured even if I have to place small fans on the Heatsinks, they should be OK with the tough load.
Can your amplifier in your avatar drive 4 ohm loads without going into magma level heat mode? If so, then is there a T0-3 transistor that could replace the 2SC5200 transistor compliment and still make around the same power levels?
Thank you for any input!
Blair
Thank you for chiming in. I am unfamiliar with all the variations and that is why I think there are a few posts regarding my wattage figures. The high powered class A JLH I am considering on 23v rails makes 28w into 8 ohms and 56w into 4 ohms.
I'm glad you responded because your amplifier is what got this whole thing started for me. I like your design and was planning on building it instead, but I ended up getting a really good deal on heatsinks pretapped for TO-3 transistors.
Most of my speakers are relatively difficult loads to drive. Some of them dipping to two ohms at certain frequencies. I'd say 3-4 ohm nom. Impedance. This is why the high power JLH seemed attractive. I figured even if I have to place small fans on the Heatsinks, they should be OK with the tough load.
Can your amplifier in your avatar drive 4 ohm loads without going into magma level heat mode? If so, then is there a T0-3 transistor that could replace the 2SC5200 transistor compliment and still make around the same power levels?
Thank you for any input!
Blair
Hello Daniel,
Thank you for chiming in. I am unfamiliar with all the variations and that is why I think there are a few posts regarding my wattage figures. The high powered class A JLH I am considering on 23v rails makes 28w into 8 ohms and 56w into 4 ohms.
I have built a JLH with just the 3055 out put stage (one per rail) and it got ~30W with 22V rails (regulated monoblock supplies) based on the williams hart kit. they sounded great but i have since sold them. the 1996 JLH is a great amplifier.
I'm glad you responded because your amplifier is what got this whole thing started for me. I like your design and was planning on building it instead, but I ended up getting a really good deal on heatsinks pretapped for TO-3 transistors.
thankyou and nice work on the heatsink buy.
Most of my speakers are relatively difficult loads to drive. Some of them dipping to two ohms at certain frequencies. I'd say 3-4 ohm nom. Impedance. This is why the high power JLH seemed attractive. I figured even if I have to place small fans on the Heatsinks, they should be OK with the tough load.
Can your amplifier in your avatar drive 4 ohm loads without going into magma level heat mode? If so, then is there a T0-3 transistor that could replace the 2SC5200 transistor compliment and still make around the same power levels?
Class A amps that operate solely in class A tend to heat up to a certain level and stabilise there hence i dont really for see a major problem driving 4 ohm loads with the hiraga or the JLH for that matter as long as your chosen output stage is up to the job - however i am currently using 8 ohm nominal speakers. (elsinores)
On the T03 side of things... There are quite alot of T03 transistors which will replace the 2SC5200/2SA1943 pair many with much higher power rating ie 200-250W, however the HF performance may not be quite as good - usually the Cob is higher due to the larger chip area to achieve the higher power rating.. like everything it is a trade off..... perhaps try MJ15024, MJL21194 style transistors.. i would suggest you may only need one pair using these.
also MJ15003 /M15003 are cheap but the Ft is not to special 🙂
Thank you for any input! - any time - i just stumbled across this thread - as i just started building my second Hiraga "Le monstre" see the PCB pic below 🙂
-Dan
Thank you for chiming in. I am unfamiliar with all the variations and that is why I think there are a few posts regarding my wattage figures. The high powered class A JLH I am considering on 23v rails makes 28w into 8 ohms and 56w into 4 ohms.
I have built a JLH with just the 3055 out put stage (one per rail) and it got ~30W with 22V rails (regulated monoblock supplies) based on the williams hart kit. they sounded great but i have since sold them. the 1996 JLH is a great amplifier.
I'm glad you responded because your amplifier is what got this whole thing started for me. I like your design and was planning on building it instead, but I ended up getting a really good deal on heatsinks pretapped for TO-3 transistors.
thankyou and nice work on the heatsink buy.
Most of my speakers are relatively difficult loads to drive. Some of them dipping to two ohms at certain frequencies. I'd say 3-4 ohm nom. Impedance. This is why the high power JLH seemed attractive. I figured even if I have to place small fans on the Heatsinks, they should be OK with the tough load.
Can your amplifier in your avatar drive 4 ohm loads without going into magma level heat mode? If so, then is there a T0-3 transistor that could replace the 2SC5200 transistor compliment and still make around the same power levels?
Class A amps that operate solely in class A tend to heat up to a certain level and stabilise there hence i dont really for see a major problem driving 4 ohm loads with the hiraga or the JLH for that matter as long as your chosen output stage is up to the job - however i am currently using 8 ohm nominal speakers. (elsinores)
On the T03 side of things... There are quite alot of T03 transistors which will replace the 2SC5200/2SA1943 pair many with much higher power rating ie 200-250W, however the HF performance may not be quite as good - usually the Cob is higher due to the larger chip area to achieve the higher power rating.. like everything it is a trade off..... perhaps try MJ15024, MJL21194 style transistors.. i would suggest you may only need one pair using these.
also MJ15003 /M15003 are cheap but the Ft is not to special 🙂
Thank you for any input! - any time - i just stumbled across this thread - as i just started building my second Hiraga "Le monstre" see the PCB pic below 🙂
-Dan
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Excellent,
This is all good information. I'm leaning towards the parallel output JLH because I have that many heatsinks, and it will help with heat dissipation to have one TO-3 per sink.
I'm not a power hog or anything, but having a little overhead will not hurt. According to the JLH high powered desigh voltage/power dissipation chart, 25v regulated rails will get around 42w into 4 and 8 ohms. As I said earlier, my speakers tend to be on the lower side in regards to impedance, so I am thinking about using the lower voltage rails to get a bit more power into the 4 ohm region.
I am planning to use the MJ15003 (2 per rail), and hope this works out well. I'm etching my boards sometime this week. I may give up and buy boards, but I'm trying etching for the first time. Should be fun!
Thanks again for the information!
Blair
This is all good information. I'm leaning towards the parallel output JLH because I have that many heatsinks, and it will help with heat dissipation to have one TO-3 per sink.
I'm not a power hog or anything, but having a little overhead will not hurt. According to the JLH high powered desigh voltage/power dissipation chart, 25v regulated rails will get around 42w into 4 and 8 ohms. As I said earlier, my speakers tend to be on the lower side in regards to impedance, so I am thinking about using the lower voltage rails to get a bit more power into the 4 ohm region.
I am planning to use the MJ15003 (2 per rail), and hope this works out well. I'm etching my boards sometime this week. I may give up and buy boards, but I'm trying etching for the first time. Should be fun!
Thanks again for the information!
Blair
Member
Joined 2009
Paid Member
Are you trying to use TO-3 just to suit the heatsinks ? - perhaps that's the wrong thing to do, it should be possible to bolt on some other types of packages ?
A JLH or any other non push pull (yes I know that the JLH is a weird sort of quasi push pull but this still applies) amp can not double its power into a load of half the resistance. You could run it of half the supply voltage and double the standing current to give the same dissipation and this would then give the same power output (give or take a few watts) as the 8R case.
I currently use a home-brewed version of the direct coupled, much modernised version of the JLH from the http://www.tcaas.btinternet.co.uk/ site but with a few changes of my own to allow very fast transistors to be used throughout without instability. Sounds very good indeed but dissipates about 160W idle and has twin cooling fans which keep it down to 48C. This gives (from memory) 25W-RMS per channel into 8R and I guess about half of that into my present 4R speakers. As they are 93dB/W it's not really an issue in my smallish flat.... could still go loud enough to get me in serious trouble😀
I currently use a home-brewed version of the direct coupled, much modernised version of the JLH from the http://www.tcaas.btinternet.co.uk/ site but with a few changes of my own to allow very fast transistors to be used throughout without instability. Sounds very good indeed but dissipates about 160W idle and has twin cooling fans which keep it down to 48C. This gives (from memory) 25W-RMS per channel into 8R and I guess about half of that into my present 4R speakers. As they are 93dB/W it's not really an issue in my smallish flat.... could still go loud enough to get me in serious trouble😀
Honestly,
Without trying to sound ignorant. Yes. My heatsinks are brand new black annodized heatsinks that I wold prefer not to drill into. Now for the creative part. Yes, I could modify them with enough transfer compound and I have even thought about how I would do this. It would not be that difficult really without tapping new holes in my heatsinks.
On the other hand, the JLH amplifiers receive great reviews and it seems like it is a clean and simple design to build. Plus, it uses the MJ15003 which just happens to be a TO-3 package transistor.
So, in essence, yes I am trying to accomodate my heatsinks, but the JLH is also a very attractive looking circuit for a first time "Scratch" build.
Blair
Without trying to sound ignorant. Yes. My heatsinks are brand new black annodized heatsinks that I wold prefer not to drill into. Now for the creative part. Yes, I could modify them with enough transfer compound and I have even thought about how I would do this. It would not be that difficult really without tapping new holes in my heatsinks.
On the other hand, the JLH amplifiers receive great reviews and it seems like it is a clean and simple design to build. Plus, it uses the MJ15003 which just happens to be a TO-3 package transistor.
So, in essence, yes I am trying to accomodate my heatsinks, but the JLH is also a very attractive looking circuit for a first time "Scratch" build.
Blair
I'm by no means a SS amp guru at all, but the JLH website uses the attached chart as a reference. Am I misunderstanding the chart? Will it not vary in output given different loads?
I'm not being arguementative by the way, but actually curious and trying to learn. I really want to hit around 40-60W per channel. My speakers are not that sensitive and my room is pretty good sized.
Thank you,
Blair
Member
Joined 2009
Paid Member
Sorry, I missed that one. If you have access to good devices in TO-3, then it makes great sense !
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