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Gain Controls Vs Volume Controls
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Author:  Cogito [ April 4th, 2021, 6:23 pm ]
Post subject:  Re: Gain Controls Vs Volume Controls
FerdinandII wrote:
All these people trying to explain the Theory of Relativity because the wrong amp in their system has the highest gain...... :crazy:


That’s not the case. Above 100Hz I have 4 horn loaded channels with about 105bB efficiency. Sub woofers are only about 93dB driven by two bridged mono amps with 400W power. Avery thing is working well with DSP crossover. Problem is, when I switchover to passive crossover, how would I level match the subs. I certainly do not wish to attenuate the Horns by about 12bB.
Author:  Cogito [ April 4th, 2021, 6:29 pm ]
Post subject:  Re: Gain Controls Vs Volume Controls
Jim G wrote:
Jim G wrote:
...I'm out of my league with the theory being discussed, but wouldn't one use an amplifier with a gain control to reduce the overall gain of the 4 way passive system to match the subs? This will reduce overall system noise as well. I can only imagine this system will be quite noisy?

...or use a much more efficient passive sub with external crossover? Mine are about 100db.


Horn loaded sub project is on my todo list. Right now, I started work in top-down approach. DAC -> Preamp -> pllxo in that order.
Author:  Jim G [ April 4th, 2021, 7:02 pm ]
Post subject:  Re: Gain Controls Vs Volume Controls
Mine aren't horn loaded but would easily keep up with your system. My full range speakers are 103db and there's tons of available gain on the crossover if needed. You're welcome to borrow one if you'd like.
Author:  Cogito [ April 4th, 2021, 8:10 pm ]
Post subject:  Re: Gain Controls Vs Volume Controls
I think I got it. I was assuming the input impedance changes depending on the position of the wiper which is technically true, except for the wiper is connected to significantly higher impedance next stage. So, the source sees entire pot impedance as load irrespective of position of wiper.

Roscoe’s messages are seldom helpful, he is cryptic and difficult to understand for someone not very well informed. And he never responded to my request for clarification. In person, he is very helpful.

Sad to say, none here tried to explain. Instead couple of people acted like jerks. Walts always does that, maybe he is still holding against me for refusing to buy the cables and bullet tweeter from him. Now, Fernidad too is now acting like Walt for some unknown reason.

This forum is not conducive to learning. There are a few people who are vey knowledgeable and helpful, people like David M, David B, Tom P, Jim etc.
Author:  Cogito [ April 4th, 2021, 9:58 pm ]
Post subject:  Re: Gain Controls Vs Volume Controls
Jim G wrote:
Mine aren't horn loaded but would easily keep up with your system. My full range speakers are 103db and there's tons of available gain on the crossover if needed. You're welcome to borrow one if you'd like.


Thx for the offer. I might take you up on the offer but, Let me get the projects in hand frond first. Modding the DAC to transformer coupling which should give me plenty of voltage so I can do with very little gain in the preamp. For that purpose, I am getting a variable gain (real gain) preamp from Transendent sound. If things work out, I want to control the volume by adjusting the gain only, no attenuation of the signal.

https://transcendentsound.com/slider.html
Author:  mix4fix [ April 5th, 2021, 12:17 am ]
Post subject:  Re: Gain Controls Vs Volume Controls
No pictures?
Author:  Pelliott321 [ April 5th, 2021, 7:37 am ]
Post subject:  Re: Gain Controls Vs Volume Controls
Shashi
If you get the TS Slider you will want to get a larger power transformer. Bruce believes you only need a power supply large enough to run the circuit.
A larger transformer will really improve things.
Author:  ratbagp [ April 5th, 2021, 4:06 pm ]
Post subject:  Re: Gain Controls Vs Volume Controls
Pelliott321 wrote:
Shashi
A larger transformer will really improve things.


Could you go into more detail?

ray
Author:  FerdinandII [ April 5th, 2021, 4:13 pm ]
Post subject:  Re: Gain Controls Vs Volume Controls
ratbagp wrote:
Pelliott321 wrote:
Shashi
A larger transformer will really improve things.


Could you go into more detail?

ray


https://youtu.be/QySiWSpaXaQ
Start at the 2:00 mark if you just want to hear the story.......
Author:  DaveR [ April 5th, 2021, 4:30 pm ]
Post subject:  Re: Gain Controls Vs Volume Controls
If the transformer is capable of providing the amount of current the circuit needs isn't it the filter caps that determine the impedance of the power supply? Instantaneous current is provided by the caps, not the transformer.
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