Hello all, I have been reading some of the posts here and have decided to build an amp for a TL Sonotube subwoofer I am planing to add to my system. I am currently using a PAS400 amp for my main speakers and want to add some bass for HT. I am an electronic engineer and have built RF linier power amps in the past so I have some experince with projects like this.
Can anyone recomend a good design for a first project? I don't want to try to design my own at this point. I have been looking at the Leach Superamp and TIM-Amp designs and they don't look to dificult and give a decent power output. I am looking for about 250W-350W to drive this sub. I am also thinking about building another one with 2 channels after I do this sub amp to replace the PAS400. It is a decent amp for mobile DJ work but I want a better sounding amp for my home setup. I have even been toying with building one with 5 Leach TIM-Amps for HT with a 5.1 processor feading it from the DVD player, but this might be to much.
I have the setup to etch my own pcb's witch is why I am looking at the Leach amps since he has kindly provided the pcb pattern on his site.
Any help on this would be greatly appreacated.
Thanks
Kerry
Can anyone recomend a good design for a first project? I don't want to try to design my own at this point. I have been looking at the Leach Superamp and TIM-Amp designs and they don't look to dificult and give a decent power output. I am looking for about 250W-350W to drive this sub. I am also thinking about building another one with 2 channels after I do this sub amp to replace the PAS400. It is a decent amp for mobile DJ work but I want a better sounding amp for my home setup. I have even been toying with building one with 5 Leach TIM-Amps for HT with a 5.1 processor feading it from the DVD player, but this might be to much.
I have the setup to etch my own pcb's witch is why I am looking at the Leach amps since he has kindly provided the pcb pattern on his site.
Any help on this would be greatly appreacated.
Thanks
Kerry
A bridged pair of low TIM amps will meet your power requirements handily, although you might want to consider Jens Rasmussen's extended Leach for reliability if you want to use it for PA. Either way use plenty of heat sink.
I used mine bridged to drive my sub for a while. My sub gets 6 db of boost at 24 Hz. Using a 1KVA transformer and 39,000 uf per 58V rail I almost never ran out of power. Some very loud LFE heavy movies challenged it, but that's about it.
Starting with a stereo amp will also give you the option to really hear its performance on the mains while using your existing sub amp. IMHO as long as there is enough power and a beefy power supply, there isn't much of an audible difference in sub amps. A plate amp for your sub and the Leach for your mains would probably give you more for your money.
I used mine bridged to drive my sub for a while. My sub gets 6 db of boost at 24 Hz. Using a 1KVA transformer and 39,000 uf per 58V rail I almost never ran out of power. Some very loud LFE heavy movies challenged it, but that's about it.
Starting with a stereo amp will also give you the option to really hear its performance on the mains while using your existing sub amp. IMHO as long as there is enough power and a beefy power supply, there isn't much of an audible difference in sub amps. A plate amp for your sub and the Leach for your mains would probably give you more for your money.
Banned
Joined 2002
Bob,
Thanks for your reply, I don't plan on using this for my pa system, I am trying to get away from the pa amp for my home system and want a good audiophile quality amp but don't want to just go out and buy one. I looked at some of the amps at Elliot Sound and liked some of them but I have read a lot of good things about the Leach amps.
My goal is to have an entire home built system so I can show it off and say I built it. I think I am going to build one of the preamps on the Elloitt Sound site but add 4 more inputs to it. One other project I have in the works is a DIY am and fm tuner. One of the guys I used to work with who is a RF engineer is helping to design these now, but the amps are the first part of this ongoing project.
You mentioned using the TIM's for the mains and a plate amp for the subs, do you know where I can get a good design for a plate amp?
Thanks
Kerry
Thanks for your reply, I don't plan on using this for my pa system, I am trying to get away from the pa amp for my home system and want a good audiophile quality amp but don't want to just go out and buy one. I looked at some of the amps at Elliot Sound and liked some of them but I have read a lot of good things about the Leach amps.
My goal is to have an entire home built system so I can show it off and say I built it. I think I am going to build one of the preamps on the Elloitt Sound site but add 4 more inputs to it. One other project I have in the works is a DIY am and fm tuner. One of the guys I used to work with who is a RF engineer is helping to design these now, but the amps are the first part of this ongoing project.
You mentioned using the TIM's for the mains and a plate amp for the subs, do you know where I can get a good design for a plate amp?
Thanks
Kerry
Actually, I was thinking of a purchased plate amp. It's awfully hard to beat something like this http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=300-796&DID=7 diy for the same money.
Any design can be made on a flatbacked heatsink mounted on a plate, if you want to go full diy. It saves the cost of an enclosure. You can substitute plastic package transistors in the Leach like Jens has done to make mounting easier.
Lots of people like the ESP amps. I have never heard them, so I won't comment. I like my Leach amps' sound. I like my A-75s a little more, just to throw out another option.
Any design can be made on a flatbacked heatsink mounted on a plate, if you want to go full diy. It saves the cost of an enclosure. You can substitute plastic package transistors in the Leach like Jens has done to make mounting easier.
Lots of people like the ESP amps. I have never heard them, so I won't comment. I like my Leach amps' sound. I like my A-75s a little more, just to throw out another option.
I have looked at that amp at Parts Express and considered it when I was originaly looking at build a standerd sub, but the design I am currently planning on is like the single driver here www.t-linespeakers.org/projects/steve/index.html . That is why I am thinknig about building a seperate amp for this and possibly expanding to 2 subs.
I have been reading the Pass DIY project site all morning and now I am torn between the Leach TIM and the A75 for the mains. Looks like I need to do some more looking ino this.
I have been reading the Pass DIY project site all morning and now I am torn between the Leach TIM and the A75 for the mains. Looks like I need to do some more looking ino this.
The A75 puts out a lot of heat - I didn't like it here in PA, so you may object to the extra air conditioning load in Texas. It can be run at lower bias, mine is set to give me about 12 watts peak in class A, which takes care of the vast majority of my listening. It then goes to class AB for the rest.
Mine are non standard - to make use of transformers I had. Rail voltage is 65 for the front end and 58 for the output. I substituted irf610 and Irf9610 for the input differential pairs, just bending the leads to fit. Originally I had IRFD210/9210s but I toasted my last set. the sound difference was minimal - seemed brighter with the 610/9610s, but then I know they have lower gate capacitance. I only use 6 pairs of IRFP240/9240 for the output stage.
My A75s seem to extract a little more low level detail than the Leach, which was significantly better at that than my Yamaha DSP-A1. Bass seems tighter and better defined with the A75.
Part count is a little lower on the A75, and I found it a little easier to build mechanically. But by the time you buy bigger heat sinks and enough extra fets for matching, it is more expensive. It also takes more tweaking to get set up. I don't know for sure, but I think I spent about $800 on each A75 and $500 on my caseless 4 channel Leach.
hope this helps you decision process
Mine are non standard - to make use of transformers I had. Rail voltage is 65 for the front end and 58 for the output. I substituted irf610 and Irf9610 for the input differential pairs, just bending the leads to fit. Originally I had IRFD210/9210s but I toasted my last set. the sound difference was minimal - seemed brighter with the 610/9610s, but then I know they have lower gate capacitance. I only use 6 pairs of IRFP240/9240 for the output stage.
My A75s seem to extract a little more low level detail than the Leach, which was significantly better at that than my Yamaha DSP-A1. Bass seems tighter and better defined with the A75.
Part count is a little lower on the A75, and I found it a little easier to build mechanically. But by the time you buy bigger heat sinks and enough extra fets for matching, it is more expensive. It also takes more tweaking to get set up. I don't know for sure, but I think I spent about $800 on each A75 and $500 on my caseless 4 channel Leach.
hope this helps you decision process
Hi Kerry,
Not to muddy the waters at all, but I recently finished my first amp. I built the ESP P101. It was a very easy amp to build and it sounds very nice. I built it three channel, figuring to use it for the front end of a 5.1 system someday. I don't have a 5.1 preamp yet so I am using it in a stereo setup and using the third channel to drive my JBL B360 Subwoofer. I have gotten nothing but complements on how good it sounds.
I am about 75% finished with my Leach Superamp. It has been a much bigger challange to built with having to make my own PCBs. Silk-screening will spoil you quick.
I hope to have the Superamp finnished within the next week. I'm not sure if you are starting before then but I will report my opinions about how the two stack up against each other, at least to my ears.
Blessings, Terry
Not to muddy the waters at all, but I recently finished my first amp. I built the ESP P101. It was a very easy amp to build and it sounds very nice. I built it three channel, figuring to use it for the front end of a 5.1 system someday. I don't have a 5.1 preamp yet so I am using it in a stereo setup and using the third channel to drive my JBL B360 Subwoofer. I have gotten nothing but complements on how good it sounds.
I am about 75% finished with my Leach Superamp. It has been a much bigger challange to built with having to make my own PCBs. Silk-screening will spoil you quick.
I hope to have the Superamp finnished within the next week. I'm not sure if you are starting before then but I will report my opinions about how the two stack up against each other, at least to my ears.
Blessings, Terry
Just how hot does your A75 run? I think after reading all the info I could find on these I am going to build a Leach for the subwoofer and an A75 for the mains.
The cost for the heatsinks isn't much of a problem right now. I have a coworker who is working part time at a custom chopper shop with a milling machine and access to lots of billet aluminum and we have been toying with some ideas for custom heat sinks. I have even tossed around the idea of liquid cooling these to a radiator placed outside.
I guess now it is time to play with Electronics Workbench and model the schematics for these and see how the parts I have in the shop will work.
The cost for the heatsinks isn't much of a problem right now. I have a coworker who is working part time at a custom chopper shop with a milling machine and access to lots of billet aluminum and we have been toying with some ideas for custom heat sinks. I have even tossed around the idea of liquid cooling these to a radiator placed outside.
I guess now it is time to play with Electronics Workbench and model the schematics for these and see how the parts I have in the shop will work.
Terry,
I would love to hear what you think of the difference between the Leach and the ESP. I have just gotten back into listening to my stereo on a regular basis after having all the components in storage for about 6 years. I finaly have a listening room large enough for my speakers (Fisher STV-766). Eventualy I want to build a realy good set of speakers as well but I am going to start with the amps. I figure it will be a couple of months before I get started on actualy building them due to sourcing parts ect...
I also have to get my bench put back together in the garage first. All my stuff has been in storage since I got married 8 yrs ago and she made me dismantle my electronics bench that was the kitchen table in my batchalor house.
I would love to hear what you think of the difference between the Leach and the ESP. I have just gotten back into listening to my stereo on a regular basis after having all the components in storage for about 6 years. I finaly have a listening room large enough for my speakers (Fisher STV-766). Eventualy I want to build a realy good set of speakers as well but I am going to start with the amps. I figure it will be a couple of months before I get started on actualy building them due to sourcing parts ect...
I also have to get my bench put back together in the garage first. All my stuff has been in storage since I got married 8 yrs ago and she made me dismantle my electronics bench that was the kitchen table in my batchalor house.
The A75 runs as hot as you want. Bigger heat sinks will lower the surface temperature, but not the amount of heat dumped to your room. Biased as directed a stereo A75 will dump close to 400 watts into your living room. I was running a little more than that before I turned it down. I don't have great air circulation in my living room, so near the amp it was noticeably hotter - 5 degrees or more.
Gee, running a space heater in the summertime and then contrasting that with the air conditioner to even things out, must make for some expensive listening. 
Maybe you should think about just attending the concerts.
How hot does the Leach amp run? My P101 is barely warm. Nothing like my Haflers.
Blessings, Terry
Maybe you should think about just attending the concerts.
How hot does the Leach amp run? My P101 is barely warm. Nothing like my Haflers.
Blessings, Terry
My 4 channel Leach is built using Apexjr 12" tunnel heat sinks. Biased at 125 mA total per channel with 59 volt rails, that's about 60 watts idling - it barely gets warm. Even after a bit of spirited listening it doesn't get very warm - I haven't bothered hooking up the fan. I'm using it to biamp my bedroom speakers, so only two channels really do much work, though.
I don't think the heat will be much of an issue in my family room where this is going to go. I have pretty good circulation and the room is about 15'x22' with a hall way on one end and the kitchen on the other so I get good flow in this room. Right now my listening position is about 15' from the system so I should be able to run as hot of an amp as possible.
I even had a crazy idea to get a larger fridge for the garage (beer cooler or kegrator) and put the amp in the dorm size fridge I have now and drill holes in the door for the input/output connectors. I never should of read the thread in the Pass section here about the Monster amp.
I even had a crazy idea to get a larger fridge for the garage (beer cooler or kegrator) and put the amp in the dorm size fridge I have now and drill holes in the door for the input/output connectors. I never should of read the thread in the Pass section here about the Monster amp.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.