6 ohm speakers are fine. If you haven't got a main transformer yet you can go with a little lower voltage one with lower impedance speakers.
I opted for a duel 0-45V output torodial transformer to drive a unknown load. Now I've settled on a 6R speaker, and it would have been better if I took jwilhelms current advice. Luckely enough the speakers I chose are a fairly easy load to drive. Just my two cents.
Why is reducing the supply voltage going to help? All in all any decent hifi amp that can handle 8 ohm loads can handle 6 ohm loads too.
An amp driving a 8 ohm speaker should be designed to safely drive a 4 ohm load. An amp driving a 6 ohm speaker should be able to safely drive a 3 ohm load. A 6 ohm speaker won't actually be a 6 ohm load through the whole frequency range, there are dips and peaks in the impedance curve. Reducing the supply voltage isn't mandatory but it makes for an amplifier they's tougher to hurt.
Another option would be to select higher power output devices. The general rule of thumb for safe output power is add the power rating of all of the output devices and divide by 5. The Honeybadger has 6 output devices. If you use 150W output devices 6 x 150 / 5 = 180W safe output power. I'm not sure if the drivers are up to it in the Honeybadger but On Semi does make some double die output devices that would fit and would increase output power handling substantially. https://www.mouser.com/datasheet/2/308/MJL4281A-D-113116.pdf
I haven't built the Honeybadger so I'm not sure if any values would need to be changed but a quick glance at the schematic looks like it will run okay with no changes.
What is the output voltage of your transformer?
Which output transistors did you go with?
And which speaker are you trying to drive?
Cheers
Tim
I haven't bought a trafo yet, the output devices I have are the ones stated in the BOM, and I am planning to pair the amp with the q acoustics 3050i.
The suggested amp is 100W/6R for those speakers. I think you would be fine with the BOM outputs (did you use the jojod version?)
FYI, I'll be driving a slightly more difficult load with mine, with a 2x 45 output 800VA transformer... I opted for MJL4281/MJL4302 for output transistors.
Ideally I think 35V or 40V secondaries could have been better, but I looked ar SOA, listening habits, and applied a large safety margin. I won't have any issues with my current set up.
My biggest problem is finding time to assemble the parts!
FYI, I'll be driving a slightly more difficult load with mine, with a 2x 45 output 800VA transformer... I opted for MJL4281/MJL4302 for output transistors.
Ideally I think 35V or 40V secondaries could have been better, but I looked ar SOA, listening habits, and applied a large safety margin. I won't have any issues with my current set up.
My biggest problem is finding time to assemble the parts!
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Just for an example/ fun...
The impedance curve for the 3050i I found on google doesn't drop below 4.5R(R is ohms). 45V secondaries would give you 63.63VDC rails. This would draw ~ 899
.75W. That's 150W per device.
Lowering the secondaries to 40V for example would cause the power to drop to 118.5W per device. Alternatively, I chose a beefier output that would handle more power(230W/ device in the case of the MJL4302)
The njw's in the BOM from the store have a power handling capability of 150W/device.
The impedance curve for the 3050i I found on google doesn't drop below 4.5R(R is ohms). 45V secondaries would give you 63.63VDC rails. This would draw ~ 899
.75W. That's 150W per device.
Lowering the secondaries to 40V for example would cause the power to drop to 118.5W per device. Alternatively, I chose a beefier output that would handle more power(230W/ device in the case of the MJL4302)
The njw's in the BOM from the store have a power handling capability of 150W/device.
This example was a simplified estimate. An other user pointed out that my rail voltage of 63.63 was higher than actual .
Just to be clear, there would be a voltage drop of approx 7 volts across the 4 input rectifier, & 6 outputs. This would be 56.63V rails.
Leaving them at 63.63 mathmatically allows For a 26% "safety margin ", which is very close to the 25% that was reccomend to me a few years back.
The math isn't perfect, just ballpark-ish.
I am open criticism.
Just to be clear, there would be a voltage drop of approx 7 volts across the 4 input rectifier, & 6 outputs. This would be 56.63V rails.
Leaving them at 63.63 mathmatically allows For a 26% "safety margin ", which is very close to the 25% that was reccomend to me a few years back.
The math isn't perfect, just ballpark-ish.
I am open criticism.
I have another question to those who built the amp: where you able to use electrolytics of bigger diameter and lead spacing than the ones stated in the BOM, and vishay dale rn60 resistors?
In post # 2010 I measured the pitch pads for all resistors.
I am not sure about the Caps, but I'm sure there was some discussion on it previously.
I am not sure about the Caps, but I'm sure there was some discussion on it previously.
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