Please excuse my ignorance.
I have a couple of monoblocks that someone on here kindly helped me sort of estimate their power output ( appx 100w )
I’m wondering is it possible to simply swap out a few components ( the big caps and mosfets? )
To increase the power output basically.
I believe the amps could possibly be musical fidelity p170 clones ( but in monoblocks as opposed to dual mono )
Also is it possible to establish the damping factor?
The reason I ask is because I have a bought some ATC SCM40 speakers which I’ve read are quite power hungry.
I have a couple of monoblocks that someone on here kindly helped me sort of estimate their power output ( appx 100w )
I’m wondering is it possible to simply swap out a few components ( the big caps and mosfets? )
To increase the power output basically.
I believe the amps could possibly be musical fidelity p170 clones ( but in monoblocks as opposed to dual mono )
Also is it possible to establish the damping factor?
The reason I ask is because I have a bought some ATC SCM40 speakers which I’ve read are quite power hungry.
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Simple answer is no 🙂
More complex answer is that you need to understand what determines the maximum 'power' output and that is normally the supply voltage value. Also remember that most listening takes place at levels of only two or three watts at most... it's true... try it yourself and see.
https://www.diyaudio.com/community/...h-voltage-power-do-your-speakers-need.204857/
More complex answer is that you need to understand what determines the maximum 'power' output and that is normally the supply voltage value. Also remember that most listening takes place at levels of only two or three watts at most... it's true... try it yourself and see.
https://www.diyaudio.com/community/...h-voltage-power-do-your-speakers-need.204857/
nice industrial look.
The simple answer to your query, to be vetted by someone knows more than me, no you cannot easily increase power.
dave
The simple answer to your query, to be vetted by someone knows more than me, no you cannot easily increase power.
dave
I absolutely agree about the first few watts but doesn’t that only apply to class A really? I very rarely listen to music remotely loud but if the ATCs need the Oomph to get the best out of them then I would surely have to increase the volume?
Perhaps I should have kept the Aleph 3 🤣
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That's two separate things really. The first watt or two are thought most important because that is where we spend most time listening. The amplifier Class (A, B, AB, D, G or H) has no impact. Whatever Class of amp you use, you still need the same voltage across the speaker to get the level you want.
Power is (voltage)^2 / resistance. So you can increase power increasing voltage or reducing load. But the former can be not supported by the amplifier and the latter can do it clipping because no sufficient current capability of the output transistors.
I agree with Dave about the look of these. There are times that I really appreciate this look and it shows that you have a quality build as well. As I understand it, a given transistor device will have a given range of output as determined By the supply voltage. In your case, I am guessing that it has been achieved already meaning they got all that they could from the transistor. I am very much shooting from the hip here, but when I see only two devices mounted on a giant heatsink, I think that the limits have already been reached.
As mentioned above, let's first find out how well the speakers are driven in your room and your music/tastes. I am betting that you will be happy. Keep us in the loop! This is always an interesting read.
As mentioned above, let's first find out how well the speakers are driven in your room and your music/tastes. I am betting that you will be happy. Keep us in the loop! This is always an interesting read.
In order to increase the power you will need to increase the supply voltage (P = E^2*R as noted above). This will likely require a new power transformer and may require new power supply capacitors. The components in the amp itself might not be able to handle the higher voltage, so you'll possibly need to swap some parts there too. Different parts have different characteristics, so this may impact the stability of the amplifier, so you need to look at that.
Higher power also means higher output current. P = I^2/R. The output devices currently in the amp might not be able to handle the higher output current. For a bipolar amp, the driver might run out of current capability, which causes the output stage to current limit.
Then there's the issue of thermal dissipation. Higher supply voltage -> higher dissipated power in the output stage. So you may need a bigger heat sink. The one that's on there looks pretty beefy, so you might be good there. But you may have to have more output devices to spread the dissipated power into more silicon area so the output devices can survive the higher dissipated power.
Is it possible to increase the power? Yes. But it may require a complete redesign of the amp; especially if you want a meaningful increase in power (say 3 dB = 2x increase in power).
If you're looking for a negligible increase, say a 10% increase (= 0.4 dB) you might be able to find a different primary tap that'll give you the required boost in supply voltage. For example if you were to run with 120 VAC mains on a primary tap designed for 110 VAC. I would personally not go this route because the difference in power is negligible but the impact on reliability could be significant - especially if you end up pushing the power supply caps right to the limit of their voltage ratings.
To paraphrase Bill Gates, "100 W ought to be enough for everybody". Unless you live in a concert hall or you have incredibly inefficient speakers, 100 W is plenty. Use the amp as-is and enjoy it. Ain't broken. Don't fix.
It looks like a quality build, by the way. If (and only if) you have issues with hum, I'd move the input wiring away from the supply wiring. If the BNC connector for the input bothers you, just get a BNC-RCA adapter. Pomona #4054 comes to mind.
Tom
Higher power also means higher output current. P = I^2/R. The output devices currently in the amp might not be able to handle the higher output current. For a bipolar amp, the driver might run out of current capability, which causes the output stage to current limit.
Then there's the issue of thermal dissipation. Higher supply voltage -> higher dissipated power in the output stage. So you may need a bigger heat sink. The one that's on there looks pretty beefy, so you might be good there. But you may have to have more output devices to spread the dissipated power into more silicon area so the output devices can survive the higher dissipated power.
Is it possible to increase the power? Yes. But it may require a complete redesign of the amp; especially if you want a meaningful increase in power (say 3 dB = 2x increase in power).
If you're looking for a negligible increase, say a 10% increase (= 0.4 dB) you might be able to find a different primary tap that'll give you the required boost in supply voltage. For example if you were to run with 120 VAC mains on a primary tap designed for 110 VAC. I would personally not go this route because the difference in power is negligible but the impact on reliability could be significant - especially if you end up pushing the power supply caps right to the limit of their voltage ratings.
To paraphrase Bill Gates, "100 W ought to be enough for everybody". Unless you live in a concert hall or you have incredibly inefficient speakers, 100 W is plenty. Use the amp as-is and enjoy it. Ain't broken. Don't fix.
It looks like a quality build, by the way. If (and only if) you have issues with hum, I'd move the input wiring away from the supply wiring. If the BNC connector for the input bothers you, just get a BNC-RCA adapter. Pomona #4054 comes to mind.
Tom
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Thanks Tom , think I’ll leave them alone . They are deathly silent bwt.
I really do like the amps , I’d love to know more about them but that won’t happen as I bought them at auction.
If they cheaped out on the heat sink, or cheaped out on the transformer, or the output transistors, or the filter caps. yes. You won't boost the peak watts but you can boost the average watts without blowup by improving one or more of those.
Your heat sink is pro grade, your filter caps are enormous for 100 w, can't see your transformer. If they have a tiny transformer covered by the 33000 uf filter caps, you could increase that a bit. In EI transformer, the more pounds of iron, the more cross section, the more watts unless you buy one with tiny windings. One pair output transistors TO220, those are pretty stressed at 100 w. You could find another board that had 2 pair output transistors.
Measure what you've got, though. Post #9. Analog voltmeter gives good reading of average AC voltage for ~$30. DVM under $150 do not. Scope, you have to measure Vpp by .35 on something that looks like a sine wave. I listen at 1vav usually, but I have 98 db 1w1m speakers. I see peaks of 25 vac sometimes in loud hits in classical music. .If I run my amp at 25 vac pretty steady, like on pop/rock, I have to wear earplugs indoors.
Your drivers are TO126 with no heat sinks, same with the VAS. If you wanted to drive 2 pairs output transistors you would have to upgrade to something like MJE15028/29 with heat sinks. You should be able to get (30^2)/8 out of +-60 v rails. I have worked on a 100 w 4 ohms Allen amp that would put out 100 watts all day during an organ competition, but the heat sink was bigger and it had one pair TO3 MJ802 output transistors.
Your heat sink is pro grade, your filter caps are enormous for 100 w, can't see your transformer. If they have a tiny transformer covered by the 33000 uf filter caps, you could increase that a bit. In EI transformer, the more pounds of iron, the more cross section, the more watts unless you buy one with tiny windings. One pair output transistors TO220, those are pretty stressed at 100 w. You could find another board that had 2 pair output transistors.
Measure what you've got, though. Post #9. Analog voltmeter gives good reading of average AC voltage for ~$30. DVM under $150 do not. Scope, you have to measure Vpp by .35 on something that looks like a sine wave. I listen at 1vav usually, but I have 98 db 1w1m speakers. I see peaks of 25 vac sometimes in loud hits in classical music. .If I run my amp at 25 vac pretty steady, like on pop/rock, I have to wear earplugs indoors.
Your drivers are TO126 with no heat sinks, same with the VAS. If you wanted to drive 2 pairs output transistors you would have to upgrade to something like MJE15028/29 with heat sinks. You should be able to get (30^2)/8 out of +-60 v rails. I have worked on a 100 w 4 ohms Allen amp that would put out 100 watts all day during an organ competition, but the heat sink was bigger and it had one pair TO3 MJ802 output transistors.
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The toroidal transformer is quite large ( compared to other amps I’ve had )
These amps don’t even get warm on the odd occasions that I turn it up .
It may not be that you need the power, the impedance hits 4Ω with an awkward phase angle means you need an amplifier that is not afraid of ugly loads. I did note that one reviewer used a NAIMNAP250 with good results… it is an amplifier that thrives on ugly loads.
dave
Could you not parallel identical power supplies? Re: isolation diodes for parallel-redundant operation. Serious headroom, no?
The only way to pull more power from that amp is to use lower resistance speakers. Like car audio people do, use 2ohm speakers. You will likely destroy the amp, same outcome like raising the power supply voltage. You seems to be hellbend on destroying someone's labor of love, go for it.
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