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LAST VALVE SOUND SIMULATOR

PostPosted: 08 Jul 2015, 06:20
by rcustoms
last valve sound simulator ,is a complete project found in the last everyday practical electronics magazine -august 2015
nirvana.jpg

this is the link
http://kat.cr/everyday-practical-electr ... ent?title=[kat.cr]everyday.practical.electronics.august.2015
realy awesome project

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 08 Jul 2015, 09:11
by DrNomis
Cheers for that Rcustoms..... :thumbsup

Note for Windows users:
To download the torrent file in Microsoft Internet Explorer, right-click on it and select "Save As" and then save it in your Downloads folder, you will also need to download/install uTorrent and 7Zip if you don't already have them installed, 7Zip is for extracting the PDF from the downloaded file.... :thumbsup

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 08 Jul 2015, 10:30
by nickthemen

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 08 Jul 2015, 15:06
by phatt
Thanks chaps, I read the artical,, Hum??
Someone may have more understanding of these things but to me that is just a fancy name for a tone control and frankly a tone control with only 3 or 4 dB of boost or cut is not something that would bother to build. Heck,,even an average parq Eq would make a bigger impression. :blackeye
Phil.

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 09 Jul 2015, 18:45
by Dirk_Hendrik
After a quick glance over the article I wondered why they did so much "right" ands then resorted to the use of 1/8" mini-jacks :?

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 09 Jul 2015, 21:29
by Ice-9
Well my isp has blocked this page due to a UK court order :(

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 10 Jul 2015, 01:59
by bajaman
check your email Mick :D

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 10 Jul 2015, 06:51
by tabbycat
if it's a good project and worth something to you, as this is the current edition of the mag you may want to consider buying it online for the price of a drink or two.
show your support for the writers and keep a good publication running.

http://www.epemag.com/

obviously if you are livng on no money at all in china, india, etc, then this is not an option and using free downloads to educate yourself is a different matter.

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 10 Jul 2015, 19:16
by Ice-9
tabbycat wrote:if it's a good project and worth something to you, as this is the current edition of the mag you may want to consider buying it online for the price of a drink or two.
show your support for the writers and keep a good publication running.

http://www.epemag.com/

obviously if you are livng on no money at all in china, india, etc, then this is not an option and using free downloads to educate yourself is a different matter.


Good idea, but I was only wanting a look, still the mag could have some other interesting stuff in it so could always be worth a buy :secret:

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 12 Jul 2015, 12:37
by teemuk
phatt wrote:Someone may have more understanding of these things but to me that is just a fancy name for a tone control and frankly a tone control with only 3 or 4 dB of boost or cut is not something that would bother to build. Heck,,even an average parq Eq would make a bigger impression


I have to agree.

Considering all the "packaging" and "marketing" involved this project is a big dissapointment.

Looking at it, it's really just a simple "waveshaper" coupled to some EQ'ing. Yes, it does recognize two of characteristics, which would be considered important ingredienmts of "tube sound" today. These would be amplitude/intermodulation distortion and non-linear frequency response due to weaker damping factor.

It's just how these issues are addressed that is terribly lacking. Yes, you will get soft distortion from an overdriven JFET but such non-linear "waveshaper" is not really going to capture all the interaction and dynamics of a typical MULTI-STAGE tube amplifier, which cascades several waveshapers.

So for "tube distortion" part this ends up being just an overdriven source follower amp. Okay. Look at just about any GUITAR AMP schematic and you'll find examples of much more ambitious and realistic schemes to fake tube amplifier's amplitude distortions. Compared to stuff employed in Peavey's TransTube amps, Crate amps, AMT pedals, Prithard amps, Quilter amps, etc. this "tube emulation" looks like a joke. If "distorting" is your only criteria for this performance, then I'll guess you'll be happy with it, though.

The other part is that EQ. Yes, tube amps with poor damping will "reflect" the impedance of the load in their frequency response since their gain changes in interaction with loading impedance. This is a recogniseable characteristic but in the end this design simply mimics the non-linear response with a filter, instead of actually doing something that really interacts with your amp/speaker load (as in what 99% of modern guitar amps do). So in the end they simply replicate some EQ curve of their preference (note that very few guitar amps are loaded by tuned cabs so the resulting response is actually different), and I agree you could just as well achieve the very same end results with a graphic EQ. ...And in practice this design is not really different from a graphic EQ design stripped to "fixed" values.

Terribly dissapointing and boring design in all regards.

I mean, how many of us haven't seen a distortion effect coupled to a "cabinet simulator" fixed EQ? I trust most of us have seen much better attempts than this.

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 12 Jul 2015, 15:04
by Groovenut
My take from having a look at the circuit is, this is meant to be a tube power amp emulator with the ability to emulate a speaker curve. Not a full blown tube amp. As such the amount of overdrive is going to be fairly subtle. I would guess the main intent for this project is as a direct recording interface. The feature set doesn't really make much sense otherwise.

Re: LAST VALVE SOUND SIMULATOR

PostPosted: 13 Jul 2015, 14:40
by phatt
teemuk wrote:
phatt wrote:Someone may have more understanding of these things but to me that is just a fancy name for a tone control and frankly a tone control with only 3 or 4 dB of boost or cut is not something that would bother to build. Heck,,even an average parq Eq would make a bigger impression


I have to agree.

Considering all the "packaging" and "marketing" involved this project is a big dissapointment.

Looking at it, it's really just a simple "waveshaper" coupled to some EQ'ing. Yes, it does recognize two of characteristics, which would be considered important ingredienmts of "tube sound" today. These would be amplitude/intermodulation distortion and non-linear frequency response due to weaker damping factor.

It's just how these issues are addressed that is terribly lacking. Yes, you will get soft distortion from an overdriven JFET but such non-linear "waveshaper" is not really going to capture all the interaction and dynamics of a typical MULTI-STAGE tube amplifier, which cascades several waveshapers.

So for "tube distortion" part this ends up being just an overdriven source follower amp. Okay. Look at just about any GUITAR AMP schematic and you'll find examples of much more ambitious and realistic schemes to fake tube amplifier's amplitude distortions. Compared to stuff employed in Peavey's TransTube amps, Crate amps, AMT pedals, Prithard amps, Quilter amps, etc. this "tube emulation" looks like a joke. If "distorting" is your only criteria for this performance, then I'll guess you'll be happy with it, though.

The other part is that EQ. Yes, tube amps with poor damping will "reflect" the impedance of the load in their frequency response since their gain changes in interaction with loading impedance. This is a recogniseable characteristic but in the end this design simply mimics the non-linear response with a filter, instead of actually doing something that really interacts with your amp/speaker load (as in what 99% of modern guitar amps do). So in the end they simply replicate some EQ curve of their preference (note that very few guitar amps are loaded by tuned cabs so the resulting response is actually different), and I agree you could just as well achieve the very same end results with a graphic EQ. ...And in practice this design is not really different from a graphic EQ design stripped to "fixed" values.

Terribly dissapointing and boring design in all regards.

I mean, how many of us haven't seen a distortion effect coupled to a "cabinet simulator" fixed EQ? I trust most of us have seen much better attempts than this.


Thanks Teemu, I was hoping someone with a deeper understanding would chime in and help clarify the details.
I lost interest when I realized they where talking about response info for hifi speakers which is a world away from guitar sound.

I note you mention AMT pedals, Any Good? Any observations would be welcomed.

I note *Bajaman* has positive comments about those units.
Thread here; viewtopic.php?f=7&t=26365
Phil.