Thanks all for the excellent advice. I will seek to add another driver/a second subwoofer and I'll look into increasing the gain of the HB. I will also try the 220uF in for C4.
All this makes me wonder if ever someone will put forth a purpose built subwoofer amp that is as good as the HB.
The HB is a rockin good amp! I guess I'm asking it to do something it was not designed to do...never a good thing. I'll leave a good thing alone.
You may try 2x330uF or even 2x470uF as you are driving a sub and nfb caps are electros. Douglas Self demonstrated how LF distortion levels drop with capacitance or how quickly they grow with (electros) capacitance decline (polypropylene caps are much better in this repect but their size...!) On on the other hand sub distortions are so much higher than those introduced by electros that going too far becomes academic...
Because of such truly high distortion levels at LF and higher power I personally prefer servo sub amps controlling diaphram movements.
cheers,
Thanks all for the excellent advice. I will seek to add another driver/a second subwoofer and I'll look into increasing the gain of the HB. I will also try the 220uF in for C4.
All this makes me wonder if ever someone will put forth a purpose built subwoofer amp that is as good as the HB.
The HB is a rockin good amp! I guess I'm asking it to do something it was not designed to do...never a good thing. I'll leave a good thing alone.
Slewmaster baby! From the designer of the HB. Pick your flavor of topologies. Boards are available here. Plenty of discussion and even a separate tread here.
Blessings, Terry
Ahhhh thank you, sombody whose feet aren't rusted to the same spot forever.
Or perhaps has a proper reading comprehension. Or both!
You are still comparing a single channel into an 8ohm speaker and a two channel amp seeing a 4ohm load. Compare that same one channel amp into a 4 ohm load and half your bridged amp into the 8 ohm speaker, which the amp sees as a 4ohm load and you will see that there is indeed no magic power, just fancy math. Besides, if you bridge that 8ohm stereo amp and plug it into a 6ohm speaker those outputs are seeing a 3ohm load. Probably need to lower the rails if you hope to stay within their limits.
that's pretty much the idea and the point of the whole consept bridging.
one ch pr speaker. or the whole darn amp on one speaker to have more power to give to THAT ONE speaker.
In this case of indoor use, a more effective signal might help a lot more than adding yet more power with a bridge amp. Probably the amplifier works just fine and therefore some of the repair needs to take place at the speaker.
Double the amp power, will add just +3db more at the speaker output, and given that the power was already excessive, I think that 3db more non-applicable generic signal won't help. Instead (instead of yet more power), some fine tuning is probably needed.
If your amp is already 240W and you added some modifications that yield 2db more useful speaker output, that is effectively similar (grossly approximately) to 400W.
Double the amp power, will add just +3db more at the speaker output, and given that the power was already excessive, I think that 3db more non-applicable generic signal won't help. Instead (instead of yet more power), some fine tuning is probably needed.
If your amp is already 240W and you added some modifications that yield 2db more useful speaker output, that is effectively similar (grossly approximately) to 400W.
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Help me spend some $$$.
I've saved about $200 for "boutique" parts, above and beyond the typical bits and pieces. I know it's a synergistic system, and you can't make chicken salad out of chicken sh"t. Parts need to work together. I'll make my own case.
So...... Spend away! Hel' it's only money!
Please be specific. ie: Power supply caps / Caps 1-6 / Silver hook up wire?
Ron
I've saved about $200 for "boutique" parts, above and beyond the typical bits and pieces. I know it's a synergistic system, and you can't make chicken salad out of chicken sh"t. Parts need to work together. I'll make my own case.
So...... Spend away! Hel' it's only money!
Please be specific. ie: Power supply caps / Caps 1-6 / Silver hook up wire?
Ron
Thanks jdg,
Is there a way to measure (and match) Q without a scope?
I've got a very nice Fluke MM but no scope.
How important is the 40,000uF per rail? I've got about 20,000uF universal duty + 10,000uf (old cap from a working Hafler DH200)
Any recommendations for 80V high quality caps? I can put 4 per rail (35mm)
63V rails
Thanks to all,
Ron
Is there a way to measure (and match) Q without a scope?
I've got a very nice Fluke MM but no scope.
How important is the 40,000uF per rail? I've got about 20,000uF universal duty + 10,000uf (old cap from a working Hafler DH200)
Any recommendations for 80V high quality caps? I can put 4 per rail (35mm)
63V rails
Thanks to all,
Ron
Over at the Nelson Pass forum there are links to how to match devices. I have not followed through on them but this winter I think I will teach myself. You can always just do a "diode test" which is to set you DMM to diode and check the resistances across the pins and group them accordingly. I did this with my HB.
About caps, I live by having caps rated at 50% above rail voltage and use 60,000 to 80,000uF per rail - basically a Nelson Pass standard power supply. Heat being the main killer of electronic parts I get caps rated for 105C if I can. The budget speaks loudly though and 85C is fine if the amp is well ventilated
About caps, I live by having caps rated at 50% above rail voltage and use 60,000 to 80,000uF per rail - basically a Nelson Pass standard power supply. Heat being the main killer of electronic parts I get caps rated for 105C if I can. The budget speaks loudly though and 85C is fine if the amp is well ventilated
Andrew T,
Very cool, looking forward to learning more about your ESR meter. (is a scope needed?)
JDG,
I'll search the Pass forums about matching devices, I think I made a jig for the BJT's. I forgot!
About Pass Power Supplies, those are Class A and the HB is Class AB. I don't know if it makes a difference or not, either way 80,000uF rails are Huge! Are you driving 12" woofers to their extensions? (kinda joking)
All my cases are built with ventilation as the primary goal equal to zero hum. I enjoy building the cases as much as solder fumes! Agree with a large safety margin (overhead) for the cap voltage.
As a general rule of thumb, Do 105* caps have better "ripple" ratings than 85* ?
Ron
Very cool, looking forward to learning more about your ESR meter. (is a scope needed?)
JDG,
I'll search the Pass forums about matching devices, I think I made a jig for the BJT's. I forgot!
About Pass Power Supplies, those are Class A and the HB is Class AB. I don't know if it makes a difference or not, either way 80,000uF rails are Huge! Are you driving 12" woofers to their extensions? (kinda joking)
All my cases are built with ventilation as the primary goal equal to zero hum. I enjoy building the cases as much as solder fumes! Agree with a large safety margin (overhead) for the cap voltage.
As a general rule of thumb, Do 105* caps have better "ripple" ratings than 85* ?
Ron
Just built a Nelson Pass f5 turbo v2, that's an AB amp. It's a darn good AB!
There ate reasons to have high cap values in a power supply and limits to what makes sense for high values. I'll leave it to the learned to debate. The F5v2 uses 80,000uF in its power supply. I built mine to spec. I listened to the HB and to the F5v2 in the context of my system in my house: F5v2 gets the main drive duty, HB drives the sub woofer.
Ripple specs are beyond my understanding, I understand heat
Cheers!
There ate reasons to have high cap values in a power supply and limits to what makes sense for high values. I'll leave it to the learned to debate. The F5v2 uses 80,000uF in its power supply. I built mine to spec. I listened to the HB and to the F5v2 in the context of my system in my house: F5v2 gets the main drive duty, HB drives the sub woofer.
Ripple specs are beyond my understanding, I understand heat
Cheers!
Does this illustrate your point? The voltage sources are equivalent to 250W-8R amplifiers (4R 500W in bridged case).
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A bridged amp puts out the same total voltage into 8 ohms as it does un-bridged into 4 ohms because that is what it sees when bridged. An amp rated for 250W per channel will only produce 1000W bridged IF it can produce 500W per channel into 4 ohms in normal operation. Of course, then to make use of it you must have an 8 ohm speaker that can actually handle 1000W.
Just built a Nelson Pass f5 turbo v2, that's an AB amp. It's a darn good AB!
There ate reasons to have high cap values in a power supply and limits to what makes sense for high values. I'll leave it to the learned to debate. The F5v2 uses 80,000uF in its power supply. I built mine to spec. I listened to the HB and to the F5v2 in the context of my system in my house: F5v2 gets the main drive duty, HB drives the sub woofer.
Ripple specs are beyond my understanding, I understand heat
Cheers!
Could you please give us a comparison between the two amps? Sound and performance wise. You've already stated your favorite.
Tell us why. Bob Ellis, I think you said you were going to build and compare as well before your surgery. If that's passed, I hope your doing well. Don't lift the amps!!!
Ron
