TC Electronic RH450 discussion - Tweaking the Preamp

[relwof]

I use the RH 450 with double bass and electric bass. I feed both instruments into a Raven Labs MDB-1, then I use the presets and footpedal from the TC for the different sounds I need -electric, pizz, arco.

For crying out loud, just because you're gonna suggestion a perfect solution before I even ask, doesn't mean that I can go back in time to buy one!!!

I don't suppose you have any idea if Steve Rabe ever made the schematics for this puppy available after retiring? Then again, maybe I really don't want to know...

Well, at least now I've got some more possibilities to research.

 

[relwof]

Oh, man, I haven't thought about bit-banging a serial port since my early Apple days, working on the Apple II.

Still pretty popular for a lot of embedded systems. Not sure what's under the hood in the RH450, but most modern embedded controllers have plenty of digital I/Os but only a handful of built-in serial I/O lines.

(For those unfamiliar, this process involves using software to send every single bit on a serial interface. It saves money in hardware, because the CPU does the work of a serial interface chip.)

Yep, and since reasonably fast, powerful embedded "CPU"s have gotten so cheap, using a plain old digital I/0 as a nearly free extra serial line is not unusual, especially for low speed I/O (which MIDI just about qualifies for these days). The down side is that the pins on the chip designed to support I/O sometimes have a bit better protection and buffering built in, so it can be easier to "burn" (i.e., fry, let the smoke out...) a bit-banged I/O channel then a buffered UART line.

 

[LM Bass]

I look forward to the final product if it becomes available. I am very happy with the head and speakers as they are, but a little tweaking could be a fun thing.

re: blending
I hear that the D-Tar Solstice does a fine job of blending. I also love the Radial bass bone, but not for piezo pickups.

 

[Vic]

And the 5-pin DIN on the back of the RH450 is certainly not a standard MIDI interface as used by the Tweaker software, since it needs bi-directional I/O (so you would need two MIDI sockets - an in and an out ). OTOH, it is plausible that, since most MIDI gear doesn't need all five pins, they wired it like a MIDI "in" port and used some of the extra pins for the "out", hence the need for a splitter cable.

Correct. MIDI only uses 2 of the 5 pins, and I can find no official MIDI spec for combining an in and an out on one connector, so this right here breaks the deal. And yeah, while the MIDI interface we were given is standard, we were also given a custom cable to combine the in/out into one connector, so you are correct in what you said about how it's all hooked together.

Well, yes and no.
On one hand, it sounds like the test setup provides bi-directional interactive control of all the normal settings you can get on the front panel and the ability to save/restore preset configurations. That makes it 100% feasible to integrate with MIDI controllers, although it might take some additional external magic (like a box which translates from proprietary TC data to MIDI CC and sysex) and special firmware in the RH450.

Understood, but if, in the end, it's so difficult to configure/support, the fact that it's possible won't outweigh the fact that it's not really practical for the vast majority of the market... kinda' to your later points.

 

[Jazzdogg]

That's a tough one. On the positive side, four bands of semi-parametric EQ is very powerful. On the negative side, the Q's are quite wide on the midrange, so you don't have the ability to 'notch cut' to control wolf tones or feedback in very specific frequencies with DB. Of course, not many amps have this ability anyway.

Also, the presets are wonderful for doubling, since everything (EQ, compression, input gain, post EQ volume, etc.) is storable. So, it is easy to have totally different voicings, input gain, etc. for your slab versus DB at the push of a button. The only downside versus a true multichannel amp is that you still only have one input... so you would need to plug and unplug the basses when switching on the gig.

Regarding piezo honk, the tight, warm voicing of the RH450, along with the relatively high input impedance would make this amp appropriate for piezo pickups (i.e., the amp natural rolls off deep bass and upper treble... the typical problem areas with piezo pickups), although I'd never use a pure, raw piezo signal without some sort of buffering anyway.

For those DBers who like a very articulate midrangey tone (like using the little GK MB150 micro combo), this head would most likely do the trick. It of course sounds awesome with slab, and will do everything short of full Marcus Miller uber sizzle.

Thanks Ken. Everything I've read about the RH450 makes me wish the EA iAmp Pro had the built-in comp, tube tone, and memories - or that the RH450 could produce comparable power.

 

[KJung]

Thanks Ken. Everything I've read about the RH450 makes me wish the EA iAmp Pro had the built-in comp, tube tone, and memories - or that the RH450 could produce comparable power.

Don't let that 450 watts hold you back. I have not heard the iAmp Pro, but I owned the 800, and the RH450 will easily keep up with that amp. Of course, it won't do that huge, sub 30hz low end that the iAmp does, but IMO that's a good thing.

This amp is quite loud!

 

[relwof]

... re: blending
I hear that the D-Tar Solstice does a fine job of blending. I also love the Radial bass bone, but not for piezo pickups.

Looks like the ToneBone PZ Pre might work as well, but both look like overkill when combined with the RH450. I think I want a very simple, clean path going in to the RH450, just switchable (or maybe blended) and properly buffered for the piezos. That's why the MDB-1 looked ideal. Besides, I suspect I'll eventually drop a preamp into the WAV4 anyhow, at which point I should be fine with a simple A/B switch, or am I missing something?

 

[relwof]

Correct. MIDI only uses 2 of the 5 pins, and I can find no official MIDI spec for combining an in and an out on one connector, so this right here breaks the deal.

I'm not sure why they originally designed it that way. OTOH, while it wasn't exactly commonplace, the practice of using the "extra" pins for proprietary features goes back a long, long way.

Understood, but if, in the end, it's so difficult to configure/support, the fact that it's possible won't outweigh the fact that it's not really practical for the vast majority of the market... kinda' to your later points.

Yeah, unfortunately that might be true. However, the points I was making relate specifically to offering an accessory/upgrade for the current production RH450s - and that still may be quite feasible, we just don't know until TC chimes in.

That said, if they don't provide a way to change settings and save/restore configurations remotely via MIDI (or some similar standard) in their next flagship bass amp, coming up with any satisfactory justification could be much harder. At that point, designing in MIDI support is simple (vs a retrofit). After all, TC obviously knows how to support MIDI, and they are doing it for products a lot cheaper than the RH450.

 

[Vic]

I'm not sure why they originally designed it that way. OTOH, while it wasn't exactly commonplace, the practice of using the "extra" pins for proprietary features goes back a long, long way.

True, and I've been in on the MIDI thing since pre 1.0 spec (back in the really early days and then later on the Amiga, years and years ago), so I'm totally in on that. I've also been generally into serial protocols of all kinds for about as long, so I have technical theories on why it is, but I don't think it'd be interesting at this point, so we'll leave it at that.

Yeah, unfortunately that might be true. However, the points I was making relate specifically to offering an accessory/upgrade for the current production RH450s - and that still may be quite feasible...

Agreed.

That said, if they don't provide a way to change settings and save/restore configurations remotely via MIDI (or some similar standard) in their next flagship bass amp, coming up with any satisfactory justification could be much harder. At that point, designing in MIDI support is simple (vs a retrofit). After all, TC obviously knows how to support MIDI, and they are doing it for products a lot cheaper than the RH450.

Well, I'd submit that's technically true, but the practical benefit may be questionable. I'm just not sure how broadly applicable or attractive it'd be to implement this via MIDI instead of just having them provide the proprietary app and then not have to worry about whatever constraints the MIDI protocol might impose. The only reason I can think of to go MIDI is if you want a sequencer to switch bass rig "patches" from song to song, or, if you'd want to use a foot controller to adjust a setting on the amp live. I just think that's REALLY REALLY fringe stuff... like a market segment that's not large enough to justify serving.

IMHO tho.

 

[Musicman20]

I took the TC RH450 test amp TC Elec have sent me tonight for the covers band rehearsals. I used the bands cheap bass, and the bands 1x12 PA cab for a monitor. I used the DI on the amp into the main PA....it sounded fantastic. It was mid-punch central. That cheap little 1x12 monitor probably wasnt enjoying it, but it sounded pretty good and the DI quality was fantastic.

On Wednesday Im getting a lift from the guitarist so ill take the RS210, the RH450 test amp, and use their bass again, just to see what difference a proper bass cabinet makes. I BET that 2x10 is easily loud enough, as every time we will play or rehearse we DI the bass.

There are reasons I use this bands backup gear btw, Im not lazy! Its a fair way to travel, and as I live in the city centre, myself and my girlfriend sold our cars as they were eating away at money and sat doing nothing. Public transport is pretty good here, but I have to be careful/sensible.

THEN, I will tweak the amp for the rehearsals/gigs after this and see what the differences are, esp at the high end.

 

[Jazzdogg]

I use the RH 450 with double bass and electric bass. I feed both instruments into a Raven Labs MDB-1, then I use the presets and footpedal from the TC for the different sounds I need -electric, pizz, arco.

Ooh, tell me more!

What cab(s) do you use with the RH450 for DB?

Have you been successful in defeating piezo honk and feedback using the RH450, or are there features on the MDB-1 that provide this functionality?

How do you like the sound?

 

[Jazzdogg]

Don't let that 450 watts hold you back. I have not heard the iAmp Pro, but I owned the 800, and the RH450 will easily keep up with that amp. Of course, it won't do that huge, sub 30hz low end that the iAmp does, but IMO that's a good thing.

This amp is quite loud!

I guess you could call me gun shy, Ken. The Shuttle 6.0 didn't provide enough oomph for all of my gigs, and neither does the iAmp 800. When a gig will be outdoors or in a large room, I usually bring my B1500, but I'd love to find a lightweight that does it all.
The feature set on the RH450 seems almost ideal; and the iAmp Pro and Carvin B2000 seem promising, powerful, and lightweight. But, the RH450 will enable me to leave my meager pedal board at home. Aaaarrrggghh! So close, and yet so far.

 

[LM Bass]

I never play loud enough to have to worry about feedback, so it's a non-issue. The MDB-1 has a really high input impedance, so it really helps piezo pickups out. I use the TC cabs, usually the 112. I don't think I will ever love the sound of amplified double bass, but this setup works well for me when I have to amplify it.

 

[Jazzdogg]

Thank you, kind sir!

 

[KJung]

I guess you could call me gun shy, Ken. The Shuttle 6.0 didn't provide enough oomph for all of my gigs, and neither does the iAmp 800. When a gig will be outdoors or in a large room, I usually bring my B1500, but I'd love to find a lightweight that does it all.
The feature set on the RH450 seems almost ideal; and the iAmp Pro and Carvin B2000 seem promising, powerful, and lightweight. But, the RH450 will enable me to leave my meager pedal board at home. Aaaarrrggghh! So close, and yet so far.

I found both the Shuttle 6 and iAmp800 lacking compared to the RH450 (both put out much less volume than you would expect from their spec, the Shuttle 6 due to that low end roll-off built in and Genz's 'interesting' way of determining the wattage of their heads, and the iAmp800 having the hi pass filter set so low that the amp spent most of its power trying to push out frequencies below 30 hz it seemed). However, in NO way will it keep up with a big lead sled like the B1500. The Rh450 would fall in-between the Shuttle 6 and B1500 regarding volume and a full, even tone IMO and IME.

 

[engedi1]

I have owned the Iamp800 and I concur with the above. It seemed to poop out on a long, loud gig, although it produced some serious bottom! I have also never been impressed with Genz Benz in any way. Most amp companies overstate their power, it is nice to see that TC is more realistic. I have found it PLENTY loud for everything I have thrown it against sofar.

 

[Sparks55]

So any recommendations on a simple, small, but high quality switch box to select between multiple basses? Maybe with buffering on one side?

Not sure what you mean about "buffering," but I've been using one of these Morley switch pedals: http://www.sweetwater.com/store/detail/ABY/
Works great and has LEDs to show which signal is going through to the amp.

Mark

 

[Vic]

Not sure what you mean about "buffering," but I've been using one of these Morley switch pedals: http://www.sweetwater.com/store/detail/ABY/
Works great and has LEDs to show which signal is going through to the amp.

Mark

By "buffering", he means rather than a simple mechanical switch device, something with some electronics contained to help with impedance issues as a result of basically adding connections to your signal chain. Then there's also electro-mechanical switching to debounce, etc. Just basically a better switching device.

 

[Sparks55]

By "buffering", he means rather than a simple mechanical switch device, something with some electronics contained to help with impedance issues as a result of basically adding connections to your signal chain. Then there's also electro-mechanical switching to debounce, etc. Just basically a better switching device.

Sounds interesting. Know of any examples? I'll be putting my bass rig together with Taurus pedals and this might come in handy.....

Mark

 

[OhulahanBass]

Any new review info???? How about on spectracomp?

Forgot my Ispot to power TLC and other pedals at rehearsal today. The Mutron has it's own weird supply and I couldn't help thinking:

"with a tweaked to limit spectracomp I can limit my slapping and Mutron without the help of any other pedal."

In the future I may end up with just the Mutron and no board if I can tweak the RH450 to limit like (or better) than the TLC.