thanks so very much, I have gotten my components ready. but what transistor is behind that tip drivers. I mean the transistor at the middle of the four TIPs.
thanks so very much for that circuit once again I will also replace the tip41 and tip42 with d718 and b688
Hi Guys
The amp shown in post-17 with +/-75V rails CANNOT use 100V devices for drivers or outputs. TIT41C42C can only be used with rails up to +/-45V maximum.
These are very slow drivers but perfectly fine for a sub amp. That application makes the idea of adding any refinements pretty much moot. Subs only go to 80Hz or so, and almost any circuit you podge together will give fantastic performance at low frequencies. The caveat is that the feedback cap to ground and the input cap should be very high in value if you want low THD.
Otherwise, very conventional compensation and other circuit attributes are the call of the day here.
If you are bridging two amps to drive a sub, there are a couple of options with regard to attaining the balanced output. One approach is to make the amps identical as noninvertting and use an inverting opamp to drive one amp. Since it is a bass amp, any opamp will suffice.
The second approach has one PA wired as unity inverting and is driven by the other PA. This approach is less ideal for DC-offset inasmuch as whatever the offset is for the first amp will be complimented by the second, doubling the net DC offset across the speaker.
If the load is 4R, each amp in a bridge effectively drives 2R to half the total power. So, a 500W 4R load looks like 2R at 250W to each amp.
Have fun
The amp shown in post-17 with +/-75V rails CANNOT use 100V devices for drivers or outputs. TIT41C42C can only be used with rails up to +/-45V maximum.
These are very slow drivers but perfectly fine for a sub amp. That application makes the idea of adding any refinements pretty much moot. Subs only go to 80Hz or so, and almost any circuit you podge together will give fantastic performance at low frequencies. The caveat is that the feedback cap to ground and the input cap should be very high in value if you want low THD.
Otherwise, very conventional compensation and other circuit attributes are the call of the day here.
If you are bridging two amps to drive a sub, there are a couple of options with regard to attaining the balanced output. One approach is to make the amps identical as noninvertting and use an inverting opamp to drive one amp. Since it is a bass amp, any opamp will suffice.
The second approach has one PA wired as unity inverting and is driven by the other PA. This approach is less ideal for DC-offset inasmuch as whatever the offset is for the first amp will be complimented by the second, doubling the net DC offset across the speaker.
If the load is 4R, each amp in a bridge effectively drives 2R to half the total power. So, a 500W 4R load looks like 2R at 250W to each amp.
Have fun
you are welcome.
That is BD139.
That will be much better if you will use D718/B688(drivers)
if you want completely remove TIP transistors u can use mje340/350 then for drivers D718/688.
That is BD139.
That will be much better if you will use D718/B688(drivers)
if you want completely remove TIP transistors u can use mje340/350 then for drivers D718/688.
You right about tip41/42 on 75v rail.im not arguing it.I said if you dont have another choise then use it.Because i was also in same situation i couldnt get 2sc4793/1837.so used tip41/42.
My big problem was heat problem on Holtons circuit.MJE340/350 they were getting hot.(75v rail).But this circuit much better in many way.it has better gain and less components most importand it is not getting hot the drivers.it is even workin with +/-12volts 🙂 and +/-75 volts.What else i can tell.im satisfied with sound and power.i bridged them using TL072 on input.one was inverting and non iverted buffers.Was amazing power.
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thanks so very much Batson. let me try to see if I will get that bd139, then I will start work on it. thanks once again
It doesnt matter.u can use mje340 or something else which you can mount on main heatsink.
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