Thanks for the tips BobEllis 🙂
The Pass F4/5 look a bit too big for me, not too keen on the class A idea yet.
The Pass F4/5 look a bit too big for me, not too keen on the class A idea yet.
You may also enjoy looking thru the assembly manual for the GT-101
https://www.akitika.com/documents/AssemblyManualGT101rev1p35.pdf
http://www.akitika.com/
https://www.akitika.com/documents/AssemblyManualGT101rev1p35.pdf
http://www.akitika.com/
Hey Djoffe, I saw that earlier today, very impressive manual! I'm definitely going to look it through carefully, really want to gather as much tips as I can 🙂
Have u seen one photo of his solder side that Terry (Still4given) has posted. NO and he has a big problem. Here, we call it a filter. This filter makes a person believe what he wants to. Observe on that thread, he ignores many answers and selects some. Don't judge a design by one persons inability to assemble it. And I suspect he is the only who has problems.
Gajanan Phadte
Gajanan, I think we are on the same side of this. I like Leach amps as a first project. I was replying to Ian Finch, who suggested Leach amps were not settled designs because Still4Given had a problem. Terry's problem turned out to be a simple device failure. Replacing the protection transistors solved his problem. Terry's amp works fine now. Yes, Terry has a rather disjointed approach to troubleshooting, but we all have our quirks.
There's lots of help here for Tinco. Even without a lot of knowledge he can build almost anything and get it running well with a minimum of equipment required.
There's lots of help here for Tinco. Even without a lot of knowledge he can build almost anything and get it running well with a minimum of equipment required.
I didn't mean it against you. Just posted that answer so that a newcomer does not take it to be the standard of the Leach. Meant nothing else.
Gajanan Phadte
Gajanan Phadte
Actually guys, the issue I hinted at with the Leach amp(s) has nothing to do with the integrity of the design or Terry's approach to problem solving. The fact is that his problems did happen and we still watch them happening. Surely it is obvious in the complexity of any design that the greater number of components will lead to a more daunting obstacles and difficulties in understanding for some. You also have to admit that original parts availability, matching requirements and basic cost are hardly optimum here for beginners who are just dipping their toes in the DIY process and be honest - we have no knowledge what the OP talents and abilities really are yet.
I actually mentor a small group young guys in building audio projects like some here on the forum even and I'm well aware of guys' limitations due to many individual factors but the worst obstacle is the age, complexity and sometimes lack of information. The Leach is fine if you can translate the parts to reasonable equivalents among those still available in thru-hole form in your region and also obtain the boards and and notes at reasonable cost. In my view though, a complex design is the wrong way to approach a first build whether it's audio or any other electronics field.
I accept that it was great project for college kids 30 years ago and I can well believe that. Complexity was a challenge that I loved back then too. The high quality sound and power remain its best features and it can still be better than a lot of designs that have come and gone since.
However, much of what is available now can also be a great build but have a greater chance of success for a wider group of people with different needs at much lower cost. All relevant matters, I'd say. As a matter of interest, I would look first at Ostripper's modern derivative - the sticky thread "honey badger" design, as a more appropriate choice for a big design with plenty of documentation and support circuitry right here on DIYaudio.
Don't forget that the need for hundreds of watts audio power is more a security blanket than a real need for the vast majority of domesic audio requirements. If we really need a monster that doubles as a motor drive or PA system, I think it best to consider that a little later on the learning curve. 😉
I actually mentor a small group young guys in building audio projects like some here on the forum even and I'm well aware of guys' limitations due to many individual factors but the worst obstacle is the age, complexity and sometimes lack of information. The Leach is fine if you can translate the parts to reasonable equivalents among those still available in thru-hole form in your region and also obtain the boards and and notes at reasonable cost. In my view though, a complex design is the wrong way to approach a first build whether it's audio or any other electronics field.
I accept that it was great project for college kids 30 years ago and I can well believe that. Complexity was a challenge that I loved back then too. The high quality sound and power remain its best features and it can still be better than a lot of designs that have come and gone since.
However, much of what is available now can also be a great build but have a greater chance of success for a wider group of people with different needs at much lower cost. All relevant matters, I'd say. As a matter of interest, I would look first at Ostripper's modern derivative - the sticky thread "honey badger" design, as a more appropriate choice for a big design with plenty of documentation and support circuitry right here on DIYaudio.
Don't forget that the need for hundreds of watts audio power is more a security blanket than a real need for the vast majority of domesic audio requirements. If we really need a monster that doubles as a motor drive or PA system, I think it best to consider that a little later on the learning curve. 😉
I couldn't have said that better myself Ian. I was re-reading the thread last night, and it seemed the overwhelming majority of advice was to start big, with a more complex project. This is quite contrary towards any project undertaking for a beginner. I thought the same thing you did, when you noted that we DON'T know the skill level, background, experience, or ability of the OP with electronics, or even if he understand the basics. All of which should be considered when offering advice. I'm just starting my Honey Badger build, but I well understand my ability and electronic knowledge - limited as it may be - to undertake such a project.
One other note... Even though there's a wealth of knowledge, experience and information on this forum, wading through the multiple threads, on related topics can be a very daunting task. Find me an expert that says, use A, and I will find you one that says use B. So it's not always an easy task to ferret out detailed information that may apply to your project. Asking a total noob to do it is just asking for trouble IMHO. Even I still find it difficult to find and relate the information on a project, and more importantly what degree of measured or sonic improvement I can expect. Much of what DIY'ers do is tweak the he&% out of a build so that the original design is long gone. How can we expect a beginner to do it!? 😱
@Tinco; Stick with a simple chipamp build, that's in as much of a kit form as possible. And I mean everything. This amp kit has been suggested earlier - and includes everything you need from unpacking it to turning it on for the first time. Good luck.
Sorry I misread you, Ian.
Yeah, electronics seemed to come easily to me so I may have been lucky building a quad of A-75s and a quad of Leach amps simultaneously as a first amp project. I had someone teach me soldering technique in person, so I was more likely to get good joints without damaging parts than a newbie on his own.
I am also a bit of a risk taker by nature, and tend to take bigger steps. A real newbie might run into problems but can wade through the forum and if the answer isn't found post a thread asking for help. There are a great number of people willing to help. Witness Terry's "help me" threads. A lot of my knowledge comes from reading troubleshooting threads. I read the problem and tried to figure out what the advice would be before reading the responses. Before long, I was able to help, at least the newbie problems.
Tinco, whether you going chip amp to build experience or jump right in as I did, read up on soldering technique. About the only way you can mess up a chip amp is to overheat it while soldering. Ironically, a colder iron is more likely to cause this than a hot one. Buy yourself a temperature controlled iron. You don't have to spend a ton - check out the cheap one at circuit specialists. I own two, set up one with a fine tip, one a broader tip. Use depends on what I am soldering.
Build a light bulb tester. It will help prevent damage if you made a mistake. It is a lot less expensive than a variac, which also helps safely power up a project for the first time.
Another test trick I like I learned from the Leach build instructions. Replace rail fuses with a 100 ohm 1/4 watt resistor when initially testing circuits with bias turned down. It took me a few burned resistors to figure out that I had placed the color coded power leads in the wrong holes on one of my Leach boards, reversing the rails. No damage was done, it still works fine 12 years later. Most chip amps will allow you to test this way, too. Class A amps, not so much.
Yeah, electronics seemed to come easily to me so I may have been lucky building a quad of A-75s and a quad of Leach amps simultaneously as a first amp project. I had someone teach me soldering technique in person, so I was more likely to get good joints without damaging parts than a newbie on his own.
I am also a bit of a risk taker by nature, and tend to take bigger steps. A real newbie might run into problems but can wade through the forum and if the answer isn't found post a thread asking for help. There are a great number of people willing to help. Witness Terry's "help me" threads. A lot of my knowledge comes from reading troubleshooting threads. I read the problem and tried to figure out what the advice would be before reading the responses. Before long, I was able to help, at least the newbie problems.
Tinco, whether you going chip amp to build experience or jump right in as I did, read up on soldering technique. About the only way you can mess up a chip amp is to overheat it while soldering. Ironically, a colder iron is more likely to cause this than a hot one. Buy yourself a temperature controlled iron. You don't have to spend a ton - check out the cheap one at circuit specialists. I own two, set up one with a fine tip, one a broader tip. Use depends on what I am soldering.
Build a light bulb tester. It will help prevent damage if you made a mistake. It is a lot less expensive than a variac, which also helps safely power up a project for the first time.
Another test trick I like I learned from the Leach build instructions. Replace rail fuses with a 100 ohm 1/4 watt resistor when initially testing circuits with bias turned down. It took me a few burned resistors to figure out that I had placed the color coded power leads in the wrong holes on one of my Leach boards, reversing the rails. No damage was done, it still works fine 12 years later. Most chip amps will allow you to test this way, too. Class A amps, not so much.
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As much as I like the idea of an LME chip based amp as a beginner project this kit looks very good and could provide the necessary parts for a future project.
Greetings to all in this tread..
Terry(still4given) did run in to some major problems with his leach amplifier and we aided with advice to help guide him along the tricky path of solving the many nagging faults he encountered. As with many pieces of equipment we must learn how it works to be able to fix it as randomly replacing parts can and will be costly.. Plus it's all to easy to forget things when one has not worked on there amplifier that has laid in waiting for 8yrs as Terry did say in his posting.
I, like most of us that use the forum are involved in audio electronics servicing on a daily basis and have to remember that not all hobbyists have the experience in fault tracking or able to know what there test equipment is telling them when things don't add up as they should do..
It can be hard going when circuits don't work correctly to the point that some re jigging of parts such as resistor values and such like that things do work....
Regards.
Terry(still4given) did run in to some major problems with his leach amplifier and we aided with advice to help guide him along the tricky path of solving the many nagging faults he encountered. As with many pieces of equipment we must learn how it works to be able to fix it as randomly replacing parts can and will be costly.. Plus it's all to easy to forget things when one has not worked on there amplifier that has laid in waiting for 8yrs as Terry did say in his posting.
I, like most of us that use the forum are involved in audio electronics servicing on a daily basis and have to remember that not all hobbyists have the experience in fault tracking or able to know what there test equipment is telling them when things don't add up as they should do..
It can be hard going when circuits don't work correctly to the point that some re jigging of parts such as resistor values and such like that things do work....
Regards.
Amptech, thank you for your troubleshooting assistance along with all the others like you who were here when I joined. I think a lot of Terry's problems are self inflicted, as he doesn't seem to follow a methodical approach to troubleshooting (same as 8 years ago). When he first discovered that the issue was protection circuit related, I would have replaced reheated the solder joints and replaced the transistors for 10 cents. As you read there, I might also have just pulled them and left it unprotected. A sound basis in basic amp theory would be helpful.
Tinco, a good source of amplifier theory is https://www.passdiy.com/project Start with the Zen series. Nelson Pass has a great teaching method and a bunch of fun projects for you along the way. If you experience problems, some basic knowledge will be helpful troubleshooting. These articles were part of what gave me the confidence to jump in at a complex level.
Tinco, a good source of amplifier theory is https://www.passdiy.com/project Start with the Zen series. Nelson Pass has a great teaching method and a bunch of fun projects for you along the way. If you experience problems, some basic knowledge will be helpful troubleshooting. These articles were part of what gave me the confidence to jump in at a complex level.
Hey I just notice I've missed a bunch of posts, for some reason I didn't get any notifications even though I had visited the last post I got a comment on.
Thanks for the cool discussion 😀 I definitely plan on doing all the testing tricks I've read in the assorted amp building guides. I also have access to a lot of cheap speakers for testing, I live ~200m from a thrift shop 🙂
So I'm having trouble deciding on a transformer. I think building the amp dual mono is the most 'cool' thing to do. Peter Daniel suggests I use one 2x22V 300VA for each channel, even though the stereo design uses the exact same transformer just once. This struck me as a bit odd/expensive, is this a normal thing to do? I know I should go with a large transformer if I can afford it, I wouldn't want to go cheap on something critical, but I just thought that going dual mono would mean I could use two smaller ones. What's the theory behind it?
So, the plitron ones he uses are affordable @ 75 euro per transformer, but Plitron won't ship orders under 200 euro :S And mouser doesn't have any transformers at 22V, only 20 and 25/24. How precise are these things? I noticed some transformers are at 220V, some at 230V and some at 234V (!?) primary, 230V is standard here (and I think everywhere in Europe). Is the circuit designed for exactly those values or can I pick one that's slightly off?
There's also cheaper Chinese ones on ebay, like this one: 1 Piece 220V 300VA Toroid Transformer 15V 22V 24V 26V 28V 32V 40V for Amplifier | eBay. Am I correct to assert that 22V * 2 * 6.5A = 286VA ~= 300VA so it would suffice? Granted ofcourse that the 0-220V is not a problem :S
Oh I just found this one, am I correct that this one is also 22V * 2 * 7.2A and 234V primary so is even closer to what I want? It's also available at mouser, so it would be ideal:
http://nl.mouser.com/ProductDetail/Hammond-Manufacturing/182N22/?qs=sGAEpiMZZMumryolnogYRnbEsYm3RV7I
Thanks for the cool discussion 😀 I definitely plan on doing all the testing tricks I've read in the assorted amp building guides. I also have access to a lot of cheap speakers for testing, I live ~200m from a thrift shop 🙂
So I'm having trouble deciding on a transformer. I think building the amp dual mono is the most 'cool' thing to do. Peter Daniel suggests I use one 2x22V 300VA for each channel, even though the stereo design uses the exact same transformer just once. This struck me as a bit odd/expensive, is this a normal thing to do? I know I should go with a large transformer if I can afford it, I wouldn't want to go cheap on something critical, but I just thought that going dual mono would mean I could use two smaller ones. What's the theory behind it?
So, the plitron ones he uses are affordable @ 75 euro per transformer, but Plitron won't ship orders under 200 euro :S And mouser doesn't have any transformers at 22V, only 20 and 25/24. How precise are these things? I noticed some transformers are at 220V, some at 230V and some at 234V (!?) primary, 230V is standard here (and I think everywhere in Europe). Is the circuit designed for exactly those values or can I pick one that's slightly off?
There's also cheaper Chinese ones on ebay, like this one: 1 Piece 220V 300VA Toroid Transformer 15V 22V 24V 26V 28V 32V 40V for Amplifier | eBay. Am I correct to assert that 22V * 2 * 6.5A = 286VA ~= 300VA so it would suffice? Granted ofcourse that the 0-220V is not a problem :S
Oh I just found this one, am I correct that this one is also 22V * 2 * 7.2A and 234V primary so is even closer to what I want? It's also available at mouser, so it would be ideal:
http://nl.mouser.com/ProductDetail/Hammond-Manufacturing/182N22/?qs=sGAEpiMZZMumryolnogYRnbEsYm3RV7I
I think it's just a matter of the nomenclature used. I believe 220v is the EU standard. Here in the US we go by both, 110v and 120v. Both mean the same thing. Average voltage at the wall can be around 112-116v. You're good with 220v rating, or whatever the published number is.
EU standard is a fudge. 230V +10%/-6%. hahaha.
I see 250V regularly.
220V rating will be fine. I run 230V stuff on 250V. No problems.
Dual mono is a bit of a gimic in my opinion. Doubt you'd notice the difference between single stereo supply and a dual mono.
I see 250V regularly.
220V rating will be fine. I run 230V stuff on 250V. No problems.
Dual mono is a bit of a gimic in my opinion. Doubt you'd notice the difference between single stereo supply and a dual mono.
mcd99uk is right in that line voltages are a fudge - a bureaucratic merging of 2 different line voltage standards on paper so that uniform regulations and distribution of products across Europe and elsewhere can be applied internationally wherever 220/240VAC grid power systems exist. Actually you still have the same supply voltage as before this change came about but a little economy with the truth never stopped bureaucracies manipulating standards. The simplest solution is to use standard products produced for use in your region rather than imports from another that may actually be to different specifications that may not be obvious. A 10% different nominal line voltage is still a 10% different nominal output voltage so still play safe.
Using the same transformer size for 2 channels is actually reasonable, as the issue of each channel's peak loading rather than total average loading being addressed and for stereo program with dual nono design, it's a valid point. However, bass is the main area of peak demand and this is almost always shared between channels so stereo designs derive little benefit from super-sized transformers. One only has to look inside commercial amplifiers to see how small the transformers really are, even on up-market audio.
Generally, it's good to purchase small parts from Mouser or Digi-key as long as you aren't being charged for Fedex express airfreight. Anything heavy like transformers , heatsinks, cases etc - buy locally. You don't say where in Europe you are but I'm quite sure local purchases of these items will wind up considerably cheaper overall than even from China. Companies like Conrad (I believe) sell a very wide range of gear and Farnell, RS have several agencies plus there are many smaller distribuitors who will save you on airfreight which can be several times the cost of the parts, even though the purchase prices may be considerably more.
I was recently quoted $147 US to freight <1lb total from Fairchild, Texas.
Last year it was $48 for a similar amount so watch freight. Sure, I live a fair distance from you guys but the same rates apply to any destination outside NA so don't assume you'll get an acceptable deal anywhere now, ex North America or Europe.
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I'm from the Netherlands, I filled in some more of my profile so you can now see our flag in next to my name 😛
Alright I found the exact transformer at a small dutch factory (Amplimo), 75 euro per piece, so I guess that's good 🙂 (2x22V 300VA ringkerntransformator - Ringkerntrafo.nl) they're even so close I could ride the bicycle over to their factory! I wonder if they'll give a discount if I do that 😀
They ship for free though, so I could also not bicycle and save my self 40km of cycling through the beautiful countryside of Twente on a lovely July day.
So I read this thread about dual mono, and I get the feeling mcd99uk is right, and it's not very necessary in this situation (especially since I plan to have it be a single case amp) http://www.diyaudio.com/forums/chip-amps/86852-why-dual-mono.html
So I'll opt for the single transformer.
Alright I found the exact transformer at a small dutch factory (Amplimo), 75 euro per piece, so I guess that's good 🙂 (2x22V 300VA ringkerntransformator - Ringkerntrafo.nl) they're even so close I could ride the bicycle over to their factory! I wonder if they'll give a discount if I do that 😀
They ship for free though, so I could also not bicycle and save my self 40km of cycling through the beautiful countryside of Twente on a lovely July day.
So I read this thread about dual mono, and I get the feeling mcd99uk is right, and it's not very necessary in this situation (especially since I plan to have it be a single case amp) http://www.diyaudio.com/forums/chip-amps/86852-why-dual-mono.html
So I'll opt for the single transformer.
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It's getting exciting! Today I received my Texas Industries sample package, which features 3 of every chipamp chip mentioned in this thread, and a few more I found interesting, all without even a shipping charge!
Then tomorrow I should be receiving my ON Semiconductor sample package, which includes 5-10 of all the rectifiers and transistors I need for this project, they charged 15$ for shipping/handling, but the transistors were actually quite expensive so its still worth it.
If Farnell's next day shipping system works correctly then tomorrow I should also be receiving all the capacitors and resistors I need, for 15 Euro total.
That leaves just the transformer, some prototype board and the actual casing (with terminals and perhaps pots). I have some ideas for the case, which I'll present later!
Do you guys think I should post more details in a separate build thread or should I just continue on here? 🙂
Then tomorrow I should be receiving my ON Semiconductor sample package, which includes 5-10 of all the rectifiers and transistors I need for this project, they charged 15$ for shipping/handling, but the transistors were actually quite expensive so its still worth it.
If Farnell's next day shipping system works correctly then tomorrow I should also be receiving all the capacitors and resistors I need, for 15 Euro total.
That leaves just the transformer, some prototype board and the actual casing (with terminals and perhaps pots). I have some ideas for the case, which I'll present later!
Do you guys think I should post more details in a separate build thread or should I just continue on here? 🙂
Good choice to start Tinco! Peter Daniel (audiosector) LM3875 kits are very easy and sound very good. just "make sure" you get at least 10000uf per rail for the power supply (kits come with 10uf caps for power supply). That kit was my first chip amp. You will get all the help from Peter daniel (He is a great guy).😉
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