TomWaits said:
I did not know you wanted to build the Krell Clone. Jens makes some very fine boards. I had an interest in the Krell Clone project, but I need to avoid Class A amps due to heat, number of amps I need to build and limited power I have in my place. The 30-0-30 400VA is a good dimension choice for the amps you are building.
Does this imply you want to try the BiPolar, AKA "Brother" version of the quasi? What Toshiba devices where you expecting to come through? What Onsemi devices are you thinking of choosing instead?
Is it IR devices or MOSFETS that you do not want in your deluxe version of your quasi's?
Have you looked at APT devices at all? There seems to be less than a handfull of APT's that look like excellent choices - like mid point between the usual IR devices and BiPolar.
Yes, no need to rush and the amps will be built when you have time and of course you have the parts you want. Clearly you know what you want for your design which is great. You also do an excellent job in yoru proeojects so the extra time and patience I am sure will be worth it once you have all of the items you want.
Sounds like you had a "Shawn's" traditional holiday
Nope, I sampled mostly small signal devices but I did manage to mix in some TO3's.
Interesting, as I could sample the power output devices. Just not sample my credit card! lol lol *hint I do not have any by choice*
They have some, just not enough quanity for what I need as many are of a suspect make.
Sadly Honson, even as Supremetronic, is not very attentive to many of there semi stock in terms or re-ordering or keeping track of their inventory, even for common use resistors. I have to say many of the power devices, including ones that are marked as Motorola and Onsemi concern me as Supremetronic, where Honson gets its inventory, is not really clear about the source of their parts other than they get them from China.
For the small signal devices I usually test some of them for Hfe knowing what the Hfe's are supposed to be and match that to the manufacture on the device to see how well they concur. Sayal's may be more likely genuine, but I cannot test them to be more certain.
I bought some Toshiba devices from Supremetronic which I have some concerns about, but until I find a better capacitance meter I cannot properly validate the junction capacitances vs the measured Hfe. I suspect I will nto really be able to sue the Toshiba devices I purchased despite my attempts to be informed, notes and pics I collected from online research. At time I was not aware of how junction capacitance can test die size non-destructively.
I find many of the local surplus stores do well on passives. There are lots of venues and sources for passives. As you know the venues for semi's is more limited due largely to the distribution agreements the large semi companies make with distributors. The distributors know this and so they are able to force people into large minimum order requirements. I suspect this is in part what the manufactures offer sampling to get about the availability and distributor policies.
Thanks about the point about order payable account. Onsemi, nor the Canadian distributor, indicated this was an alternate means to order/pay for samples.
Cheers,
Shawn. Happy New Year!
Time to go back to fixing some buggy code I have been trying to debug for few weeks. I found the source of bug, now all I need to do is fix the bug and possible related bugs that the code may have. Then I can go back to the original task at hand.
Some may have wondered why I suggested another 8-9 months before I can build my first quasi amp. Part of that is my guess when I can find remaining parts for a single stereo amp and work on the PCB changes or refinements I need to do or need to merge into the base board changes I have done so far., most related to the high level of demands software demands at the level I work at with software.
Shawn, keep to your plan what you want in your amp, even if it means waiting for the parts you want or you decide to use a desireable alternate.
Regards,
John L. Males
Willowdale, Ontario
Canada
06 January 2007 03:10
Hi Andrew,
The odd DIY project will not hurt them. It's the abuse that can happen that will call in the accountants. They are already looking. In other words, it's okay to be a very small problem.
Hi John,
The cost at Sayal may be higher, but travelling is a higher cost still. Web orders are wonderful things for that reason. So if you bought 5 of each, what is the differential cost to you? That's what you need to think about.
Wouldn't it be nice if distributors actually did stock the entire line of popular devices?
-Chris
The odd DIY project will not hurt them. It's the abuse that can happen that will call in the accountants. They are already looking. In other words, it's okay to be a very small problem.
Hi John,
The cost at Sayal may be higher, but travelling is a higher cost still. Web orders are wonderful things for that reason. So if you bought 5 of each, what is the differential cost to you? That's what you need to think about.
Wouldn't it be nice if distributors actually did stock the entire line of popular devices?
-Chris
Hi Chris,
Are you suggesting Onsemi feels there may be some concerning abuse for samples, as opposed to a small problem?
Traveling costs as far as I am concerned is not a cost, nor is my time as rule. Reason being is I do not drive so my travel costs are fixed. As far as time is concerned places like Sayal or even more so the surplus stores about that I will go to have changing inventory which a actual visit for things I may have on my list now, waiting for in no hury, etc are discovered when they otehrwise would not be. Many of these stores are downtown where I make frequent trips for anyway. The discovered items or their excellent price savings offsets any time and/or travel costs in my opinion. As a business both the time and travel would be cost factors, as hobbyist the case for most part in my opinion.
Web ordering for sure has many upsides. For me skipping fact I cannot web order as I do not have any Credit Cards by choice for basically 15 years (had one a couple years ago and they kept messing up from administrative perspective so cancelled card after less than a year.) these companies usually ship via courier and I am not home when they arrive most of time, skipping the rude cost of their brokerage fees. Shipping via mail is best for me both from brokerage fee and convience perspective. The Canada Post brokerage fee is flat, not the sliding scale of item value (not the duty part, just the broker fee to clear) price scale brokerage fees courier companies use. If I am not home I can pick up at postal outlet which is about 10 minute walk away. If I have to go for pickup for most of the courier companies it is usually a rather long distance, the balance are a long distance, not to mention hours for pickup are less flexible. Do no get me started if the shipment is via UPS. Simply put, I refuse to have anything shipped to me via UPS Canada. If a business only ships UPS then I do not do business with them, that simple.
Regards,
John L. Males
Willowdale, Ontario
Canada
06 January 2007 13:21
Are you suggesting Onsemi feels there may be some concerning abuse for samples, as opposed to a small problem?
Traveling costs as far as I am concerned is not a cost, nor is my time as rule. Reason being is I do not drive so my travel costs are fixed. As far as time is concerned places like Sayal or even more so the surplus stores about that I will go to have changing inventory which a actual visit for things I may have on my list now, waiting for in no hury, etc are discovered when they otehrwise would not be. Many of these stores are downtown where I make frequent trips for anyway. The discovered items or their excellent price savings offsets any time and/or travel costs in my opinion. As a business both the time and travel would be cost factors, as hobbyist the case for most part in my opinion.
Web ordering for sure has many upsides. For me skipping fact I cannot web order as I do not have any Credit Cards by choice for basically 15 years (had one a couple years ago and they kept messing up from administrative perspective so cancelled card after less than a year.) these companies usually ship via courier and I am not home when they arrive most of time, skipping the rude cost of their brokerage fees. Shipping via mail is best for me both from brokerage fee and convience perspective. The Canada Post brokerage fee is flat, not the sliding scale of item value (not the duty part, just the broker fee to clear) price scale brokerage fees courier companies use. If I am not home I can pick up at postal outlet which is about 10 minute walk away. If I have to go for pickup for most of the courier companies it is usually a rather long distance, the balance are a long distance, not to mention hours for pickup are less flexible. Do no get me started if the shipment is via UPS. Simply put, I refuse to have anything shipped to me via UPS Canada. If a business only ships UPS then I do not do business with them, that simple.
Regards,
John L. Males
Willowdale, Ontario
Canada
06 January 2007 13:21
Hi Shawn,
My goodness. You ordered those 2SK1530 some months ago if I recall. I did a bit of hunting on internet, as I thought these were Hitachi only devices. I discovered Toshiba also made them as well. When you said Toshiba devices you were waiting for I thought you decided to use something different. Obviously at this point it is not the case. Hopefully the Toshiba 2SK1530's will arrive for you to build your deluxe Quasi's.
Regards,
John L. Males
Willowdale, Ontario
Canada
06 January 2007 23:14
My goodness. You ordered those 2SK1530 some months ago if I recall. I did a bit of hunting on internet, as I thought these were Hitachi only devices. I discovered Toshiba also made them as well. When you said Toshiba devices you were waiting for I thought you decided to use something different. Obviously at this point it is not the case. Hopefully the Toshiba 2SK1530's will arrive for you to build your deluxe Quasi's.
Regards,
John L. Males
Willowdale, Ontario
Canada
06 January 2007 23:14
Hi John,
One thing that's important to know about the Japanese semiconductor industry. Only one manufacturer makes a type number. If another manufacturer makes a similar or identical (in specs) device, it is given a different number. Knowing this will help you not get burned with a fake.
-Chris
One thing that's important to know about the Japanese semiconductor industry. Only one manufacturer makes a type number. If another manufacturer makes a similar or identical (in specs) device, it is given a different number. Knowing this will help you not get burned with a fake.
-Chris
Hi Chris,
I find a rather big mix of those Japanese transistors (and some other semiconductors) where in fact the very same part number is used by the company making the similar/clone of the part as the original company. In the case of the 2SK1530 I had only seen Hitachi datasheets, so I incorrectly assumed in this case only Hitachi made the 2SK1530.
I am sure you are more versed than I amin this audio stuff. As one example I am sure you know Phillips, OnSemi, Fairchild all make many of the BC devices. All respectable companies and respective part, but by no means the only companies that make many of the common BC devices. I know some of the other companies making BC devices have variences to the "standard" respective BC part they make. Some of these variences in the respective company datasheet are often not an issue for a design, some are. Usually those devices or concern have specs that are of different from the well known spec in more than one regard and usually these datasheet spec'ed variences are on the side of not as suitable for audio use, at least.
Now of course then there are the parts for known companies known for their substandards in many respects who still call and label the part the same number.
I have at time come across MOSPEC devices in my parts search. I know little about this company so I have avoided them and have been able to do so. I know when I look at many of the general, and even some higher end consumer, audio equipment I see at least the output power devices are not a name I know at all or odd time a MOSPEC. Rarely do I observe a well known part in them. That in itself motivates me much more to build my own, not buy.
I have and do take my meter to check the Hfe of the transistors I am considering buying to help confirm if they are a Phillips, OnSemi, Motorola, Toshiba, Fairchild, et al knowing the the Hfe grades and markings as part of how I confirm if a part is likely genuine. This is partly because some well known companies adn the space on a TO-92 case is so small it is hard to read, or more likely space is so limited to put much on the device even from well known companies.
My first amp was one I built and it was a tube amp when I was a teenager. My next one was the famous Sinclar modular design. I still have it. My mom tossed my tube amp as she did many other things when she so felt inclined. I bought a Radio Shack 50W amp in late mid 1970's until I could build my own. It was an ok amp and surved me well for number years. I used it longer that I intended and it was able to due to nagging switch contact problem that developed I could never resolve. There were a few amps along way I wanted to build, but many of the low and medium level transistors were just impossible to find locally through the 1990's. I stumbled into the quasi amp of this thread and volia - a base design I favoured for about a year, but not able to find a design with stability or still some local parts availability problems.
Then as I am "collecting" all the parts I need for the quasi amps a amp showed up in stores, actually two amps from different companies. One looked like was a cheap Chinese HT amp for about $200.00. Not bad, but not great from parts used perspective. After few months it disappeared from shelves and a stereo amp with a toroid and real Toshiba devices for driver and output stage appeared that also had a number of other simple inexpensive elements for some reason only reserved for some of the > $800.00 HT units and none of the stereo units. It had excellent thermal protection and the price was $80.00 so I bought one to be interm replacement to the Radio Shack amp I had for 30 years. My, the difference was great and at the price really cheaper than if I did a DIY of a 2SC5200/2SA1943 based amp when toroid, case, heatsink were all factored in. DC offset is about 16mv on this stereo amp. Not bad. I tested the thermal limit and found basically using full sine wave I the thermal cuts in just a bit above the 50% point of the volume control. Once the temperature drops down the amp realy connects back in and plays again. Not bad. The normal running temperature of the amp is very cool and only that full sign wave test made it heat up. Even though much heat still raised out the amp after the signal level was brought down the amp played just fine and cooled to the usual cool operation it has while I play from it. Sadly this amp was only carried in the store for a couple months at best. Sad as frankly speaking it was better than models if higher price and up to more than 4 times its price.
The same company made a HT version of same design. The stores never carried it, but I lucked out finding someone locally that was selling it in new condition. I bought it. There has not been one I have seen offered for sale at all in the 9+ months since. The HT version added digital inputs, 4 A/V inputs, 6 channel input, DSP, DTS/Pro Logic II, excellent management and options for the control of the HT speakers and modes, etc., but the same amps an devices (of course toroid) and most of the outputs DC offset are 1.5 mv.
My point is even in the commerical designs it seems one either pays big $$ for ones using the genuine semiconductor parts, often do for no name parts an generally most consumer and mid level consumer products use no name parts. Of course for the DIY type they can avoid all of this consumer mess except I suspect for the HT specific DSP and decoder elements.
Regards,
John L. Males
Willowdale, Ontario
Canada
07 January 2007 20:25
07 January 2007 20:39 Corrected a rash of typo errors, and fear some bad ones still exist. jlm
I find a rather big mix of those Japanese transistors (and some other semiconductors) where in fact the very same part number is used by the company making the similar/clone of the part as the original company. In the case of the 2SK1530 I had only seen Hitachi datasheets, so I incorrectly assumed in this case only Hitachi made the 2SK1530.
I am sure you are more versed than I amin this audio stuff. As one example I am sure you know Phillips, OnSemi, Fairchild all make many of the BC devices. All respectable companies and respective part, but by no means the only companies that make many of the common BC devices. I know some of the other companies making BC devices have variences to the "standard" respective BC part they make. Some of these variences in the respective company datasheet are often not an issue for a design, some are. Usually those devices or concern have specs that are of different from the well known spec in more than one regard and usually these datasheet spec'ed variences are on the side of not as suitable for audio use, at least.
Now of course then there are the parts for known companies known for their substandards in many respects who still call and label the part the same number.
I have at time come across MOSPEC devices in my parts search. I know little about this company so I have avoided them and have been able to do so. I know when I look at many of the general, and even some higher end consumer, audio equipment I see at least the output power devices are not a name I know at all or odd time a MOSPEC. Rarely do I observe a well known part in them. That in itself motivates me much more to build my own, not buy.
I have and do take my meter to check the Hfe of the transistors I am considering buying to help confirm if they are a Phillips, OnSemi, Motorola, Toshiba, Fairchild, et al knowing the the Hfe grades and markings as part of how I confirm if a part is likely genuine. This is partly because some well known companies adn the space on a TO-92 case is so small it is hard to read, or more likely space is so limited to put much on the device even from well known companies.
My first amp was one I built and it was a tube amp when I was a teenager. My next one was the famous Sinclar modular design. I still have it. My mom tossed my tube amp as she did many other things when she so felt inclined. I bought a Radio Shack 50W amp in late mid 1970's until I could build my own. It was an ok amp and surved me well for number years. I used it longer that I intended and it was able to due to nagging switch contact problem that developed I could never resolve. There were a few amps along way I wanted to build, but many of the low and medium level transistors were just impossible to find locally through the 1990's. I stumbled into the quasi amp of this thread and volia - a base design I favoured for about a year, but not able to find a design with stability or still some local parts availability problems.
Then as I am "collecting" all the parts I need for the quasi amps a amp showed up in stores, actually two amps from different companies. One looked like was a cheap Chinese HT amp for about $200.00. Not bad, but not great from parts used perspective. After few months it disappeared from shelves and a stereo amp with a toroid and real Toshiba devices for driver and output stage appeared that also had a number of other simple inexpensive elements for some reason only reserved for some of the > $800.00 HT units and none of the stereo units. It had excellent thermal protection and the price was $80.00 so I bought one to be interm replacement to the Radio Shack amp I had for 30 years. My, the difference was great and at the price really cheaper than if I did a DIY of a 2SC5200/2SA1943 based amp when toroid, case, heatsink were all factored in. DC offset is about 16mv on this stereo amp. Not bad. I tested the thermal limit and found basically using full sine wave I the thermal cuts in just a bit above the 50% point of the volume control. Once the temperature drops down the amp realy connects back in and plays again. Not bad. The normal running temperature of the amp is very cool and only that full sign wave test made it heat up. Even though much heat still raised out the amp after the signal level was brought down the amp played just fine and cooled to the usual cool operation it has while I play from it. Sadly this amp was only carried in the store for a couple months at best. Sad as frankly speaking it was better than models if higher price and up to more than 4 times its price.
The same company made a HT version of same design. The stores never carried it, but I lucked out finding someone locally that was selling it in new condition. I bought it. There has not been one I have seen offered for sale at all in the 9+ months since. The HT version added digital inputs, 4 A/V inputs, 6 channel input, DSP, DTS/Pro Logic II, excellent management and options for the control of the HT speakers and modes, etc., but the same amps an devices (of course toroid) and most of the outputs DC offset are 1.5 mv.
My point is even in the commerical designs it seems one either pays big $$ for ones using the genuine semiconductor parts, often do for no name parts an generally most consumer and mid level consumer products use no name parts. Of course for the DIY type they can avoid all of this consumer mess except I suspect for the HT specific DSP and decoder elements.
Regards,
John L. Males
Willowdale, Ontario
Canada
07 January 2007 20:25
07 January 2007 20:39 Corrected a rash of typo errors, and fear some bad ones still exist. jlm
Stay Tuned Folks
I am drafting a layout for a compact version of the amp. It will use 4 x TO220 devices for the output stage and will be half the size of the 6 FET board. It will not have DC detect on board but it will allow the user to combine a multichannel system in a very compact way. The layout will use a single ended heatsink bracket allowing the constructor to mount multiple PCBs on one heatsink.
The prototype will use 4 x IRF840 / 830.
Cheers
Q
I am drafting a layout for a compact version of the amp. It will use 4 x TO220 devices for the output stage and will be half the size of the 6 FET board. It will not have DC detect on board but it will allow the user to combine a multichannel system in a very compact way. The layout will use a single ended heatsink bracket allowing the constructor to mount multiple PCBs on one heatsink.
The prototype will use 4 x IRF840 / 830.
Cheers
Q
Hi John,
Historically, Pro Electron numbers and Jedec numbers are made by numerous suppliers. With Japanese (JIS) numbers, the one company only uses that number. Second source companies may be confusing the issue in present times.
Therefore, if I want to buy 2SK170 types and they don't say Toshiba, I ain't buying. Those are probably fakes. Same goes for 2SC2922 or 2SA1216 or any other Toshiba (or JIS) part.
Most companies do not buy fakes when manufacturing something. In some countries they make a similar device, and so mark it similarly but differently. An example would be 2SA and KSA numbered parts. There are times the pin out is different as well. Like we needed that confusion!
Now there are factories in China making probably every part with the original number. This is their own semiconductor industry. I wish they had some something similar to what the Koren industry did (KS series).
-Chris
Historically, Pro Electron numbers and Jedec numbers are made by numerous suppliers. With Japanese (JIS) numbers, the one company only uses that number. Second source companies may be confusing the issue in present times.
Therefore, if I want to buy 2SK170 types and they don't say Toshiba, I ain't buying. Those are probably fakes. Same goes for 2SC2922 or 2SA1216 or any other Toshiba (or JIS) part.
Most companies do not buy fakes when manufacturing something. In some countries they make a similar device, and so mark it similarly but differently. An example would be 2SA and KSA numbered parts. There are times the pin out is different as well. Like we needed that confusion!
Now there are factories in China making probably every part with the original number. This is their own semiconductor industry. I wish they had some something similar to what the Koren industry did (KS series).
-Chris
Hi Chris,
Would it be fair to say in essense many of the parts by second source companies are confusing the part number landscape, fakes excluded?
I like your comment if a distributor does not state the company that makes the part, as in your 2SK170 example. Is there a reference one can go to to find who the oroginal part was designed by? I assume there are various venues like diyAudio people that can offer their comments on second source parts of same part number, some of which may be better than OEM. I have heard many of the IRF part number MOSFETS Harris made as an IRF second source part number were better than the IRF OEM according to may that were supposed to be in the know.
How many times have we heard those saying check the pin outs if use diferent part or from different manufacture in advance and when something is amiss just after a build is complete. I think the motivation for the different pinouts is to make a PCB layout more convient, even if it is a misplaced motivation.
Interesting you mention KS and Korea. I have some KSA340/KSA350's which I believe are made by Fairchild. Fairchild also makes an MJE340/MEJ350. The difference basically seems to be the KSA's are an all plastic TO-126 case style compared to the MJE's which are like the original MJE's with a bit of metal about the rear part of the TO-126 hole. Thermally I am not sure what the net difference is between the two. The MJE's need an insulating pad between the heatsink whereas the the KSA's do not. At least in this case there are different part numbers to differentiate the metal about rear of mount hole and all plastic version.
Regards,
John L. Males
Willowdale, Ontario
Canada
07 January 2007 22:09
Would it be fair to say in essense many of the parts by second source companies are confusing the part number landscape, fakes excluded?
I like your comment if a distributor does not state the company that makes the part, as in your 2SK170 example. Is there a reference one can go to to find who the oroginal part was designed by? I assume there are various venues like diyAudio people that can offer their comments on second source parts of same part number, some of which may be better than OEM. I have heard many of the IRF part number MOSFETS Harris made as an IRF second source part number were better than the IRF OEM according to may that were supposed to be in the know.
How many times have we heard those saying check the pin outs if use diferent part or from different manufacture in advance and when something is amiss just after a build is complete. I think the motivation for the different pinouts is to make a PCB layout more convient, even if it is a misplaced motivation.
Interesting you mention KS and Korea. I have some KSA340/KSA350's which I believe are made by Fairchild. Fairchild also makes an MJE340/MEJ350. The difference basically seems to be the KSA's are an all plastic TO-126 case style compared to the MJE's which are like the original MJE's with a bit of metal about the rear part of the TO-126 hole. Thermally I am not sure what the net difference is between the two. The MJE's need an insulating pad between the heatsink whereas the the KSA's do not. At least in this case there are different part numbers to differentiate the metal about rear of mount hole and all plastic version.
Regards,
John L. Males
Willowdale, Ontario
Canada
07 January 2007 22:09
Re: Stay Tuned Folks
Your design is pretty compact by reducing to 4 devices and chopping off the DC detect. I have a version of that kicking around here somewhere. I have another version with PSU on board. I'm planning to do the 5.1 thang with the Qautro all wheel drive. 
Some day when the day is 48 hours long.
It would be nice to see what you cook up!
Cheers,
Shawn.
quasi said:
Your design is pretty compact by reducing to 4 devices and chopping off the DC detect. I have a version of that kicking around here somewhere.
I have another version with PSU on board. I'm planning to do the 5.1 thang with the Qautro all wheel drive. Some day when the day is 48 hours long.
It would be nice to see what you cook up!
Cheers,
Shawn.
Re[02]: Stay Tuned Folks
Quasi,
Interesting development. I assume there have been many such requests. I hinted at the desire some months ago, but in the current PCB layout. I advised you later I could tweek the current PCB (all be it manually via a graphics editor program) so you did not need to make a TO-220 version. Clearly there there is also a camp wanting smaller physically and power wise as there was a high demand for a more powerful version. This is clearly a vote of how wonderful your design is - reliable, flexible, easy to build and excellent sonics.
What would you be rating the 4xIRF840/30 pair version wattage as 100/200W 8/4 Ohms? The respective rail voltage you are targeting?
I am in no hurry for this compact TO-220 version, but I am very keen to see the PCB when you post it and the target power.
I trust you, your family and the pets had a good holiday season.
Regards,
John L. Males
Willowdale, Ontario
Canada
07 January 2007 23:04
Quasi,
Interesting development. I assume there have been many such requests. I hinted at the desire some months ago, but in the current PCB layout. I advised you later I could tweek the current PCB (all be it manually via a graphics editor program) so you did not need to make a TO-220 version. Clearly there there is also a camp wanting smaller physically and power wise as there was a high demand for a more powerful version. This is clearly a vote of how wonderful your design is - reliable, flexible, easy to build and excellent sonics.
What would you be rating the 4xIRF840/30 pair version wattage as 100/200W 8/4 Ohms? The respective rail voltage you are targeting?
I am in no hurry for this compact TO-220 version, but I am very keen to see the PCB when you post it and the target power.
I trust you, your family and the pets had a good holiday season.
Regards,
John L. Males
Willowdale, Ontario
Canada
07 January 2007 23:04
TomWaits said:
On Friday I ordered 100 each MPSA42/92 !
I'll get a nice little piece of foam and a six pack of beer and try to sort 'em out.
"sort" = by Hfe?
Have you seen my post for "Polar T1000 Assistance":
http://www.diyaudio.com/forums/showthread.php?s=&threadid=93599
I know you likely will not know how to fix it, but it might prove useful in "sorting" if I find someone that might be able to assist.
Edit: spelingg
lol lol lol lol ... Are you starting to receive some of my genes via these postings Shawn?
Regards,
John L. Males
Willowdale, Ontario
Canada
07 January 2007 23:14
heyyyy , helllo quasi
how r ya ? remmeber me ?
lol , thanks for ur great amp i built the 350w version bout 6 month ago , for my band as a guitar amp and we r all so satisfied w it ...
i remember u draw a smaller version w 4 FETs i wanna build it for a freind band , but i couldn t find the page u attached the files . can u plzzz attach it again . or gimme the page no. if u remember
i ll be so grateful
thanks
bye,
how r ya ?
remmeber me ? lol , thanks for ur great amp
i built the 350w version bout 6 month ago , for my band as a guitar amp and we r all so satisfied w it ... i remember u draw a smaller version w 4 FETs i wanna build it for a freind band , but i couldn t find the page u attached the files
. can u plzzz attach it again . or gimme the page no. if u remember i ll be so grateful
thanks
bye,
Ahmad_tbp said:heyyyy , helllo quasi
how r ya ?
lol , thanks for ur great amp
i remember u draw a smaller version w 4 FETs i wanna build it for a freind band , but i couldn t find the page u attached the files
i ll be so grateful
thanks
bye,
Hi Ahmad, great to see your amp is still going. It must get some heavy use as a guitar amp. I think Tom Waits (Shawn) and Keypunch (John) have modified the board for 4 FETs. Well Gentlemen?
Cheers
Q
quasi said:
Quasi, Ahmad, Shawn,
I have the stock quasi 4 pair version board. Saddly I cannot post to the forum as I cannot reduce the file size to be below the 100K forum file limit in the 20 minutes I have right now. I have to go out until this evening and I am late getting out door as tried to quickly reduce image below 100K limit. If you can wait until this evening I will have more time to try to reduce the image file size or put up a temp link to it. Sorry about the delay.
There is a 4 board version at the site I put up just a shade over a year ago. If Ahmad wants to pull that down just be sure to erase the extra Vbe trace that Shawn found that likely Ahmad may wish to fix in the band version at some point by cutting the trace out. I have not had the time to update the site of late. I tried to about few months ago but some bugs in the site administration consumed quite some time and the site people still have not figured the problem out, but I by luck in their assistance have a temporary workaround in place after a couple months of effort.
The version of board I was trying to reduce in size right now has the Vbe trace correction (extra one taken out) in the PCB image.
Regards,
John L. Males
Willowdale, Ontario
Canada
08 January 2007 09:30