Relevant to the mains filter discussion:
The Sound of the Machine
(please scroll down to "Power Supplies and Noise Spectra")
Thanks,
Alex
The Sound of the Machine
(please scroll down to "Power Supplies and Noise Spectra")
Thanks,
Alex
I still worry that the opportunity for making things worse (and dangerous) is there for the average punter. In a studio you can make sure everything inside the padded door is under your control. With a domestic unit there is always the chance of them doing something daft with a mix of isolated and non-isolated power outlets and not even enough understanding!
Just to be clear I believe audio transformers are good when used correctly and when the installation is large enough to have problems.
While I am not opposed to it, it seems that threads which get very technical go about ten posts then die on the vine. I am very interested in transferring what I've been lucky to learn to the next generation. There doesn't seem to be much interest. Kind of like the Cuba sonic attack thing..
Jn
Comes with the territory, very few understand the hardcore tech stuff and don't feel capable of contributing.
The problem becomes a deliverable, something that is useful to someone that is genuinely interested but is not capable of creating the solution.
Hi Howie,
I frequently use as a separate transformer -- useful also for ultra low T&M test levels -- the exceptional isolation transformers made by TOPAZ Ultra-Isolation Transformer mfr.
They are often available on e-Bay at various VA ratings. Highly recommended for ground isolation. The best in that category IMO.
THx-Richard
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EQUI=TECH says:
Article 647 in the 2002 NEC says
Section 250.30 in the 2002 NEC
Separately Derived Systems | IAEI Magazine
YouTube
George
Thanks
As is now (no added mass, no fibreglass in between), close acoustic coupling of these two drivers has this transfer function.
I think of using driving LF signal at 73Hz (resonance) and 3100Hz HF at the monitored driver
George
Attachments
Hmm. I thought the idea was to connect the cones with a shaft of some sort and drive them directly. I would think the other driver's behavior will be less important with air coupling though.
It would probably be better to have them coupled through a box that was stuffed with old socks, then you don't have to contend with reflections affecting the coupling between cones. But then again, what do I know. I guess you had the idea of putting a sheet of cloth or or something between them?
BTW, what is the deal with that EI core like magnet structure I see on older speakers? It is good, bad, ugly?
It would probably be better to have them coupled through a box that was stuffed with old socks, then you don't have to contend with reflections affecting the coupling between cones. But then again, what do I know. I guess you had the idea of putting a sheet of cloth or or something between them?
BTW, what is the deal with that EI core like magnet structure I see on older speakers? It is good, bad, ugly?
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Easy to compare how behaves as a microphone at low frequency and 10kHz the speaker that drives the other. Don't forget it is powered by an amplfier, so hightly damped by its low ouput impedance for reflexions of the 10 KHz. And we don't care, anyway, this speaker is only here to make the menbrane of the one we measure moving at low frequency, while we measure what's happens at 10KHz.
I am not sure the resonnance frequency of the assembly is the best choice for the low frequency: we want maximum excursion and maximum coupling (IE very low frequency), we don't care about maximum acoustic power.
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Well, I thought of starting with the easy to do/no damage acoustic coupling and see how it goes.
Next step, stuffing the area btn cones with pillow filling material.
The construction you see was common for small wide band alnico magnet drivers. It worked well (a common problem after many years and some bad handling is mechanical position shifting of the alnico barrel. Coil rubs or stucks.)
I would prefer to use lower freq but I am afraid at very low frequences (1-10Hz) there will be increased pressure leakage, thus not maximum coupling (I may be wrong though.
Yes. In these measurements here, the driving source has an Ro of 150 Ohm
George
Attachments
As it's friday:
Vinyl | Free Plug-in
I like this from their ad copy ' It’s all the lo-fi sounds you want, with none of the lo-fi sounds you don’t.'.
I also like the 'year' dial so you can have 80s.70s, 60s, 50s or 30s vinyl effects.
But I am most intrigued as to how they have modelled warp as a de-warping alogrithm doesn't exist...
Vinyl | Free Plug-in
I like this from their ad copy ' It’s all the lo-fi sounds you want, with none of the lo-fi sounds you don’t.'.
I also like the 'year' dial so you can have 80s.70s, 60s, 50s or 30s vinyl effects.
But I am most intrigued as to how they have modelled warp as a de-warping alogrithm doesn't exist...
While this arrangement would attenuate the magnetic interference, it would add a multi-pole acoustic transfer function of the tube, with the first one at about 565Hz for a tube length of 1 foot at room temperature.
Regards
Some however do keep going and articles like Scott's on digital RIAA are a much viewed reference for some of us for whom the day job means we keep forgetting. But I agree that some of these topics rapidly become a graveyard. I have some theories on how to prevent that that I have tested in a limited form.
I've got to polish up my forgotten groundwork before I can start to understand the advanced stuff sadly. Still no time like the present
And yes I still intend to start a grounding thread one day...
Funny. As if it is intended for the anti-audiophile. For the person who finds DAB radio quality too much to bear?
I would also like to see an Edison wax cylinder effect.
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