Just viewed some UTUBEs of Bogner discussing a Rupert Neves Transformer addition to some pedals and the influence the reactor adds to the tone.
Is it possible to place a Mag Amp or other type of saturatable reactor in the signal path prior to the power amp to add harmonics to the tone of an amp? Well really it must be since that is what Bogner has done. What would it look like in practice?
Caveat would be the limitations on frequencies so there would have to be some sort of mix or bypass of the original signal.
SATURABLE REACTORS
The Saturable Reactor consists of two core and coil assemblies each with two AC coils and two DC coils.
Two assemblies are required to avoid inducing AC voltage into the DC circuitry. The DC winding provides the ‘variable-saturation' of the cores and so forces the AC reactance of the assembly to change. It is made of M6 Grain Oriented Steel laminations/ or square B-H lamination as desired by the application and Nomex insulated copper windings. Together with the linear reactor the saturable reactor provides part of a variable voltage divider, which effectively slides the output voltage up and down, effectively providing voltage regulation.
Saturateable Reactors in the Signal Path
Moderators: pompeiisneaks, Colossal
Saturateable Reactors in the Signal Path
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Re: Saturateable Reactors in the Signal Path
Along the same lines as the Cry Baby Fasel inductor? http://www.geofex.com/Article_Folders/w ... m#inductor
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Re: Saturateable Reactors in the Signal Path
"MagAmp" is an entirely different concept than transformer coupling.
There are few examples of MagAmp concept used for entire audio amplification from preamp stages to power amp. In practice it intoduces much more additional complexities than benefits. Essentially it is very similar to class-D (switching semiconductors are replaced by switching coils) but difficulties start from sourcing the actual "MagAmp" coils and developing the HF/HT modulator required by the scheme.
Judging by Rupert Neve Designs / Bogner pamflets we seem to be talking about Bogner using ordinary audio coupling / impedance matching transformers manufactured by RNS. Nothing to do with MagAmps whatsoever.
Saturated signal coupling transformer is an entirely different matter. Especially in guitar amps saturation is rare because it requires rather low frequencies, it also sounds horrible when it really happens. Also, it's not that easy to saturate small signal transformers in 9VDC-powered effect boxes because of low voltages and limited bandwidth of guitar signals. Usual influence to tone from signal coupling transformers are just usual bandwidth limitation characteristics - which are usually escalated by "way off" mismatches between source and load impedances, or proper inductances related to the transformer coupling. Quite many people tend to mistaken these effects as "transformer saturation". In ideal design such transformers are naturally completely "transparent", and I think the RNS transformer is more or less manufactured to serve such idea. Or is it deliberately a subpar component marketed as high quality?
There are few examples of MagAmp concept used for entire audio amplification from preamp stages to power amp. In practice it intoduces much more additional complexities than benefits. Essentially it is very similar to class-D (switching semiconductors are replaced by switching coils) but difficulties start from sourcing the actual "MagAmp" coils and developing the HF/HT modulator required by the scheme.
Judging by Rupert Neve Designs / Bogner pamflets we seem to be talking about Bogner using ordinary audio coupling / impedance matching transformers manufactured by RNS. Nothing to do with MagAmps whatsoever.
Saturated signal coupling transformer is an entirely different matter. Especially in guitar amps saturation is rare because it requires rather low frequencies, it also sounds horrible when it really happens. Also, it's not that easy to saturate small signal transformers in 9VDC-powered effect boxes because of low voltages and limited bandwidth of guitar signals. Usual influence to tone from signal coupling transformers are just usual bandwidth limitation characteristics - which are usually escalated by "way off" mismatches between source and load impedances, or proper inductances related to the transformer coupling. Quite many people tend to mistaken these effects as "transformer saturation". In ideal design such transformers are naturally completely "transparent", and I think the RNS transformer is more or less manufactured to serve such idea. Or is it deliberately a subpar component marketed as high quality?
Very Informative
Thanks for the very informative answer. That clears up the subject for me.
I previously had a discussion regarding the use of Mag Amps in the output section as a power control device and the same issues came up regarding the Horrid sound that would result.
Regards,
Silverfox.
I previously had a discussion regarding the use of Mag Amps in the output section as a power control device and the same issues came up regarding the Horrid sound that would result.
Regards,
Silverfox.
Re: Saturateable Reactors in the Signal Path
For sure it's not easy to make them sound right, and for sure they need to be chosen really small if we want them to saturate simmetrically. Same concept if we want to add a little bit of DC to saturate asimmetrically.
Anyway I wouldn't say they sound bad, it's just not so easy to make them sound in the right way, like all other circuits.
Anyway I wouldn't say they sound bad, it's just not so easy to make them sound in the right way, like all other circuits.
How to employ
Unfortunately I don't even have a complete idea of what I'm trying to imagine but I think this is closer than the original Mag amp concept.pdf64 wrote:Along the same lines as the Cry Baby Fasel inductor? http://www.geofex.com/Article_Folders/w ... m#inductor
Using an inductor to generate harmonics in to sweeten the sound. I'm not thinking of a Wah sound though. Rather the sweetening that comes from the harmonics induced by an inductor. How could the inductor here be employed in the signal chain to fatten the tone? Or is that even possible to get the output transformer qualities aroma from a smaller inductor.
Your Link: http://www.geofex.com/Article_Folders/w ... m#inductor
btw- Just took a listen to Redwing. A three piece really needs a great bass to carry the Mojo particularly through the Lead Guitar solos. Sounds like you've got it.
Silverfox.