I have the boards!!
#1 - will fill the BOM from mouser , mouser has a "shared cart" option.
I must learn the mouser way to "share" my cart (XML format) , then all the
premium parts (ha ha) that I pick will be a click away.
#2 - Since I have 4 boards (really!! ... guys) I will make 2 "flavors" of the badger...
one bjt input and one FET!!! input.
#3 - having the actual boards ... I can source the best components (looks +
specs) from the best distributors. --- mouser , digikey , even ebay (noble 5W .22R 10mm LS emitter resistors).
R9-10 are base stoppers to end any high gain CCS oscillation. R14 is a Douglas Self addition (read the book).
These boards are BEAUTIFUL !! I will use 2 for parties
, the other 2 will be "lab'ed" to show the ultimate scope of this universal AB amp. (6 different amps on one board) ... that is how I designed it !!OS
I have the boards!!
#1 - will fill the BOM from mouser , mouser has a "shared cart" option.
I must learn the mouser way to "share" my cart (XML format) , then all the
premium parts (ha ha) that I pick will be a click away.
#2 - Since I have 4 boards (really!! ... guys) I will make 2 "flavors" of the badger...
one bjt input and one FET!!! input.
#3 - having the actual boards ... I can source the best components (looks +
specs) from the best distributors. --- mouser , digikey , even ebay (noble 5W .22R 10mm LS emitter resistors).
R9-10 are base stoppers to end any high gain CCS oscillation. R14 is a Douglas Self addition (read the book).
These boards are BEAUTIFUL !! I will use 2 for parties
, the other 2 will be "lab'ed" to show the ultimate scope of this universal AB amp. (6 different amps on one board) ... that is how I designed it !!OS
Stuffing my boards right now and wanted to express a little frustration: Some of the holes are a *little* too small. I'm not sure what the hole sizes are, but...
R6 on one of my boards had to be reamed out. The lead diameter of my resistor is 0.64mm.
R43-R48 had to be reamed on both boards. My lead diameter: 1.02mm.
C8, C18, C19 - Mica caps are fairly limited on Mouser. I had to get 500V versions for these three: lead diameter of 0.8mm.
Maybe on the next board spin these could be opened up a little. This is slowing me down!
R6 on one of my boards had to be reamed out. The lead diameter of my resistor is 0.64mm.
R43-R48 had to be reamed on both boards. My lead diameter: 1.02mm.
C8, C18, C19 - Mica caps are fairly limited on Mouser. I had to get 500V versions for these three: lead diameter of 0.8mm.
Maybe on the next board spin these could be opened up a little. This is slowing me down!
Please don't take this as complaining, just trying to help make a better product.
On the back of the HB board there's solder mask covering C18 and C19. I scraped it off with a razor blade.
There's also mask over the "C-R-Z" jumpers in the cascode.
I didn't solder in any jumpers though, because there are already traces on the top layer.
...still a few days from firing it up. hopefully not in the literal sense.
On the back of the HB board there's solder mask covering C18 and C19. I scraped it off with a razor blade.
There's also mask over the "C-R-Z" jumpers in the cascode.
I didn't solder in any jumpers though, because there are already traces on the top layer.
...still a few days from firing it up. hopefully not in the literal sense.
Fet input? Oh, is this perchance, an integrated buffer, so that my laptop source can produce flat non-shout midband response and really rockin bass? Well, that performance does take a buffer and integrated would be really cool.
I ran into the same issue, except with almost all my resistors..Stuffing my boards right now and wanted to express a little frustration: Some of the holes are a *little* too small. I'm not sure what the hole sizes are, but...
R6 on one of my boards had to be reamed out. The lead diameter of my resistor is 0.64mm.
R43-R48 had to be reamed on both boards. My lead diameter: 1.02mm.
C8, C18, C19 - Mica caps are fairly limited on Mouser. I had to get 500V versions for these three: lead diameter of 0.8mm.
Maybe on the next board spin these could be opened up a little. This is slowing me down!
Luckily I have access to a chemical lab at work and was able to etch the leads on the resistors instead of drilling the boards, that sped up things greatly.
Practically everything you require may be found in the store link here:
The diyAB "Honey Badger" Class AB Power Amp - 150W/Channel (2 Channels) - PCBs
Low voltage operation exception
"And don't put a resistor in the tail of the input stage pair "
" The notional function of the resistor in the tail was to minimize the damage if the tail current-source transistor failed short-circuit "
" The unwanted result was that these amplifiers would not work on very low rail voltages.... " Douglas Self
"And don't put a resistor in the tail of the input stage pair "
" The notional function of the resistor in the tail was to minimize the damage if the tail current-source transistor failed short-circuit "
" The unwanted result was that these amplifiers would not work on very low rail voltages.... " Douglas Self
Yes particularly during power down.
I have a PCB from one of our very reputable amp designers and it whistles for about half the power down period (~15seconds).
That is quite unacceptable. To me that is an amplifier failure.
I have now incorporated an output relay with delayed start, instant off and DC detect. This hides the problem. It does not cure the instability on falling supply rail voltage.
I have another that sends repeated thumps to the speaker as it powers down. Again a design failure. But this time I modified the the PSU layout by separating the low current stages from the high current stage with a high value RC filter. I suspect that I have a motorboating problem. This time I have incorporated a design failure by using a well recommended modification. Again I could hide the problem with an output relay.
I have a PCB from one of our very reputable amp designers and it whistles for about half the power down period (~15seconds).
That is quite unacceptable. To me that is an amplifier failure.
I have now incorporated an output relay with delayed start, instant off and DC detect. This hides the problem. It does not cure the instability on falling supply rail voltage.
I have another that sends repeated thumps to the speaker as it powers down. Again a design failure. But this time I modified the the PSU layout by separating the low current stages from the high current stage with a high value RC filter. I suspect that I have a motorboating problem. This time I have incorporated a design failure by using a well recommended modification. Again I could hide the problem with an output relay.
Perhaps it could be said that signal coupling transformers are not a solution to DC at the source,
since DC flow in the primary could saturate the core and ruin performance.
I think that an interstage audio coupling transformer designed to handle a few watts even, would have
little trouble from say, the output of a single rail transistor preamp or a balanced rail Opamp design.
Just be sure to talk with your bank's credit manager before buying one that approaches hi-fi quality.
SQ is another issue and frankly, a top quality film/foil cap will beat any transformer on fidelity,
however cool the idea of using a transformer somewhere in your system currently is.
since DC flow in the primary could saturate the core and ruin performance.
I think that an interstage audio coupling transformer designed to handle a few watts even, would have
little trouble from say, the output of a single rail transistor preamp or a balanced rail Opamp design.
Just be sure to talk with your bank's credit manager before buying one that approaches hi-fi quality.
SQ is another issue and frankly, a top quality film/foil cap will beat any transformer on fidelity,
however cool the idea of using a transformer somewhere in your system currently is.
A request for help...
The DIYaudio store is updating the webpages of the various PCB and other products.
We would like to have better descriptions of the amps so interested parties can get a good sense of what the product is, does, etc... to better inform his choice.
I've done a few of the Firstwatt clones so far - (None are complete yet, but you will get the general idea.)
F-5 clone boards (2 PCBs, makes 2 channels; Rev 2.0) - First Watt Clones - Power Amplifiers - Circuit Boards
F-4 clone boards (2 PCBs, makes 2 channels; Rev 2.0) - Power Amplifiers - Circuit Boards
Aleph J (2 PCBs. Makes 2 channels. Rev 2.0) - Circuit Boards
In general, the store people don't know enough about this amp to make an informed description/flyer/blurb. Espicially as the PSU requirements are such a wide net. Any info would be greatly appreciated.
Can you help? This would be a great chance to give a few moments than can help support the forums. Just put it into this thread and I will assemble all the pertinent bits. (you can see that there is even a decent amount of copy/paste that will work from the Firstatt-style amps. )
Here is the copy of one of those if you don't want to open the other page -
```````````````
Details
This pair of F-5 Clone circuit boards use the same circuit as the Nelson Pass / Firstwatt F-5 model.
Circuit Description
The F5 is a Push-Pull, Class-A power amplifier. It is unique in that it has no capacitors in the amplifier circuit. The F5 is a voltage source amplifier, requiring nothing out of the ordinary from your preamp or speakers.
The F5 is probably the most popular amplifier being built on DIYaudio these days. It is simple to make, sounds fantastic, and has similar gain to many commercial amps.
Populate these boards with your components, then add your own power supply, chassis and heat sinks to complete the amplifier. The mounting hole spacing is the same as all other diyAudio Version 2 UMS boards.
Output power
25WPC into 8ohm
Power supply requirements
A Bipolar power supply of (+/- 24V) is required. This will require an 18V+18V (or 36V Center Tapped) transformer from 300-500VA, and PSU capacitance of 30,000uF per rail or more. The PSU for the F4, F5, and Aleph J are all essentially identical. See the F5 build guide for details.
Chassis suggestions
The 4U Deluxe Amplifier Chassis makes a great home for this amplifier, and has pre-tapped holes that match the circuit board and transistor mounting positions. The DIYaudio "Universal Mounting Spec" (UMS) is a common mounting pattern between the amplifier PCB and the heatsinks. If you utilize the UMS on your heatsinks or use one of the pre-drilled chassis from DIY audio, you will be able to quickly and easily mount different amplifier boards in the same chassis. For example, a 4U 'Jack of all Chassis' with a 400VA, 18V+18V transformer and PSU board, will give you a power supply and chassis where you could try the F4, F5, F5C, Aleph J, and other Pass/Firstwatt amps in the future merely by swapping the amp PCB. The investment in Chassis and PSU needs only be made once.
Please see the F5 thread in the store support forum for any questions you might have and a definitive list of relevant links and resources.
`````````
Thank you in advance,
-Jim
The DIYaudio store is updating the webpages of the various PCB and other products.
We would like to have better descriptions of the amps so interested parties can get a good sense of what the product is, does, etc... to better inform his choice.
I've done a few of the Firstwatt clones so far - (None are complete yet, but you will get the general idea.)
F-5 clone boards (2 PCBs, makes 2 channels; Rev 2.0) - First Watt Clones - Power Amplifiers - Circuit Boards
F-4 clone boards (2 PCBs, makes 2 channels; Rev 2.0) - Power Amplifiers - Circuit Boards
Aleph J (2 PCBs. Makes 2 channels. Rev 2.0) - Circuit Boards
In general, the store people don't know enough about this amp to make an informed description/flyer/blurb. Espicially as the PSU requirements are such a wide net. Any info would be greatly appreciated.
Can you help? This would be a great chance to give a few moments than can help support the forums. Just put it into this thread and I will assemble all the pertinent bits. (you can see that there is even a decent amount of copy/paste that will work from the Firstatt-style amps. )
Here is the copy of one of those if you don't want to open the other page -
```````````````
Details
This pair of F-5 Clone circuit boards use the same circuit as the Nelson Pass / Firstwatt F-5 model.
Circuit Description
The F5 is a Push-Pull, Class-A power amplifier. It is unique in that it has no capacitors in the amplifier circuit. The F5 is a voltage source amplifier, requiring nothing out of the ordinary from your preamp or speakers.
The F5 is probably the most popular amplifier being built on DIYaudio these days. It is simple to make, sounds fantastic, and has similar gain to many commercial amps.
Populate these boards with your components, then add your own power supply, chassis and heat sinks to complete the amplifier. The mounting hole spacing is the same as all other diyAudio Version 2 UMS boards.
Output power
25WPC into 8ohm
Power supply requirements
A Bipolar power supply of (+/- 24V) is required. This will require an 18V+18V (or 36V Center Tapped) transformer from 300-500VA, and PSU capacitance of 30,000uF per rail or more. The PSU for the F4, F5, and Aleph J are all essentially identical. See the F5 build guide for details.
Chassis suggestions
The 4U Deluxe Amplifier Chassis makes a great home for this amplifier, and has pre-tapped holes that match the circuit board and transistor mounting positions. The DIYaudio "Universal Mounting Spec" (UMS) is a common mounting pattern between the amplifier PCB and the heatsinks. If you utilize the UMS on your heatsinks or use one of the pre-drilled chassis from DIY audio, you will be able to quickly and easily mount different amplifier boards in the same chassis. For example, a 4U 'Jack of all Chassis' with a 400VA, 18V+18V transformer and PSU board, will give you a power supply and chassis where you could try the F4, F5, F5C, Aleph J, and other Pass/Firstwatt amps in the future merely by swapping the amp PCB. The investment in Chassis and PSU needs only be made once.
Please see the F5 thread in the store support forum for any questions you might have and a definitive list of relevant links and resources.
`````````
Thank you in advance,
-Jim
Those of you who have built the Honey Badger amp... what is the ballpark cost for an entire 2-channel amp? Keyword being ballpark. I don't need the cost itemized, but just wanted to make sure the items shown below are included in the estimate.
(1) AMP PCBs
(2) PSU PCB
(3) Complete component BOM for amp and PSU
(4) Heat sinks
(5) Tranny
(6) Suitable enclosure (I know this one can vary a lot)
(7) Misc. items
Thx,
Rick
(1) AMP PCBs
(2) PSU PCB
(3) Complete component BOM for amp and PSU
(4) Heat sinks
(5) Tranny
(6) Suitable enclosure (I know this one can vary a lot)
(7) Misc. items
Thx,
Rick