Yamaha THR10C Physical Modeling Guitar Amp: The Best Physical Modeling Guitar Amp?

Since the commercial proliferation of physical modeling DSP based guitar effects and amps since the early 1990s, does the 21^st Century era Yamaha THR10C physical modeling guitar amp the best of them?

By: Ringo Bones 

Unlike the Yamaha THR10X which is geared more towards harder edged foot pedal dependent Texas Blues and heavy metal electric guitar tone, I only acquired the Yamaha THR10C because it was offered recently as a bargain in our local pawn shop and given that it is already out of warranty, my previous familiarity of its internal DSP / physical modeling circuitry allowed me to perform mods that allowed me to fit an external bigger speaker – i.e. a 15-inch electric guitar speaker with whizzer cone either by Celestion, Eminence, or Jensen or any other great old model or to connect it to another solid state guitar amp that has nary a physical modeling DSP preamplifier stage – to fully test out whether physical modeling DSP / digital signal processing based electric guitar amps had really progressed sonically or are still stuck in the post Operation Desert Storm euphoria of the early 1990s and only the ergonomics had evolved. 

Priced at around 450 US dollars when it hit the market during the middle of 2013, the Yamaha THR10C or specifically the amp’s DSP / physical modeling circuit – according to Julian Ward of Yamaha UK – was originally developed from the physical modeling technology used for the 1993 era VL1 Synth, thus explains my familiarity of the amp’s innards given I was repairing and servicing something like it since the end of Operation Desert Storm. Given that the other DSP based physical modeling guitar amp I can compare it side-by-side with is the 1997 era Line 6 AxSys 212, all I can say is makers of physical modeling amps completely missed the boat market-wise of the mid to late 1980s hair metal boom where such devices would have proved a godsend if they where available in their mid to late 1990s incarnations. 

With its 24-bit  A/D D/A converters sampling at 44.1KHz to guarantee 16-bit fidelity Redbook CD ready tone, the Yamaha THR10C’s five settings really proved useful if your preferred genre of music is 1960s era electric Blues and early 1970s era Classic Rock. Sadly, the Yamaha’s built-in small speakers will be found wanting when you crank it up in a beer pub gig setting. With the mod I recently did, every working musician in my neighborhood who use the Yamaha THR10C as their main gig amp in the local beer pubs in our neighborhood are now paying me to have theirs with a switchable option to hook up a 15-inch external electric guitar speaker with whizzer cone like the Eminence Red Coat Big Ben model or similar mounted in an open baffle. Sadly when used in such configuration, such a revealing external speaker as the 15-inch Eminence allows you to hear the “quantization noise (?) / or very low level click-click noise” of the Yamaha THR10C’s physical modeling DSP chip when you crank the amp’s volume to have it roaring at around the 110 dB SPL level. Sadly, to my audiophile trained ears at least, physical modeling DSP guitar amps are indeed really stuck in the time of post Operation Desert Storm euphoria of the early 1990s in terms of sonic performance. Although once you switch back to the built in tiny speakers, it allows you to practice in relative silence without the threat of eviction, divorce or arrests for disturbing the peace. But like all physical modeling DSP based guitar amps produced since then, its recording options will easily allow you to record AC/DC like electric guitar tones without resorting to cranking up your amp to play at AC / DC concert volume levels – i.e. 120 to 130 dB sound pressure levels. 

But if you’re involved in a cover band whose guitar tones are more akin to Avril Lavigne’s first two albums, the Line 6 AxSys 212 with its patent pending Tube Tone physical modeling DSP system is a better choice because such guitar tones can easily be had by twiddling the Line 6 AxSys 212 controls. It took me between 45 minutes to an hour toying with the Line 6 for the first time back in 2004 when I bought one after it was offered as a bargain in our local pawn shop. The 1989 Soldano Super Lead Overdrive setting is a good starting point in the Line 6 by the way. Inexplicably, Line 6’s top of the line products are “conventional” vacuum tube based electric guitar amplifiers equipped with either the EL34, EL84 and 6L6 output tubes – as opposed to solid-state based electric guitar amps with a physical modeling DSP tube emulation based preamplifier stage. Tone wise, it seems that all physical modeling DSP based solid-state electric guitar amps I’ve tested so far is stuck in the early 1990s – only the ergonomics and ease of desktop PC recording connectivity had improved which explains why high fidelity solid state integrated amplifier manufacturers still had never used these physical modeling DSP chips into the preamplifier sections of their amps so far. 

Using Aging Tubes: A Dangerous Guitar Tone Tweak?

Though very, very rarely mentioned in interviews by superstar guitarists, is the use of aging tubes to create your very own unique guitar tone very dangerous to your very expensive gear?


By: Ringo Bones


I’ve probably lost count since 1997 on how many guitarists around my neck of the woods explored in finding ways to make their renditions of Veruca Salt’s Earthcrosser intro sound more “soulful”, especially by resorting to tone tweaks that could irreparably damage to their extremely expensive (3,000 US dollars MSRP) electric guitar amplifier. From connecting four 8-ohm speakers in series to a push-pull based tube electric guitar amp – which could result in a very high voltage build up of the output power tubes – to using aging tubes. Though by far, the use of aging tubes is the most common. Given that tubes are becoming very scarce compared to latest generation mobile phones – especially in the US – the “poor” unsigned amateur guitarist is more than likely be using output power tubes in his or her electric guitar amplifier that are past its prime.

I’ve read an article about the summer NAMM 1992 in Guitar Player magazine about a company introducing a digital electric guitar effects processor - with an effects setting - that emulates the sound of an aging tube, such tone never became popular. Even during the guitar-heavy musical genre of Seattle Grunge that went mainstream a few months after reading that feature.

Given that I’ve only began building and owning tube-based amplifiers in the mid 1990s, I’ve asked some veteran audiophiles on how an aging power tube sounds in a “hi-fi audio setting.” Most of them pointed out the “quirky acoustics” of the Tori Amos song China from the Little Earthquakes album as what music would sound like when played through a tube amp with output power tubes past its prime and will be arcing anytime soon.

Back in April 2009, I was asked to help an amateur unsigned guitarist who wants his performance to be video recorded for You Tube posting. He was using a family heirloom 1965 Fender Twin Reverb with aging 6L6 tubes. He did manage to conjure up a very unique tone until 30 minutes into the session when one of the 6L6 tubes started to arc and fused into its tube sockets, though it did manage to emit a very cool apocalyptic-sounding high-pitched squeal when the final chord was struck.

Given that equipment of this vintage still uses plastic / phenolic resin output power tube sockets for the 6L6 output tubes / valves instead of being upgraded to military-spec porcelain tube sockets with silver plated contacts when it became widely available during the mid-1990s. Fortunately, only the output section of his Fender Twin was damaged. But it resulted in a very expensive repair bill, especially when you live in a place where most people live on slightly less than a dollar a day.

It is still a mystery why guitar digital effects processors still don’t add an aging tube emulator proviso on its menu of effects, especially ones that do advanced 24-bit 96-kHz digital signal processing are now relatively cheap and widely available. An aging tube sound / tone obtained through digital domain physical modeling is a much safer way of doing things compared to using actual aging tubes on your very expensive tube-based electric guitar amp since complete catastrophic failure resulting from such practice is not that far from impossible. Maybe guitar effects manufacturers are ignoring this sector of the market at their own peril since the sound of an aging tube is very interesting and very soulful.