Clarus I Series iii Input Jack

[John Stephen]

I'm hoping somebody out there might know the answer to this one. My search didn't turn up a response, so here goes. I have an old Acoustic Image Clarus I (series III) amp head, rated at 400 watts. It has one input jack, which is a combined 1/4-inch/XLR jack. Does anyone know if that input jack can handle a line-level signal, or is it strictly instrument-level/mic level? Thanks in advance.

 

[agedhorse]

I'm hoping somebody out there might know the answer to this one. My search didn't turn up a response, so here goes. I have an old Acoustic Image Clarus I (series III) amp head, rated at 400 watts. It has one input jack, which is a combined 1/4-inch/XLR jack. Does anyone know if that input jack can handle a line-level signal, or is it strictly instrument-level/mic level? Thanks in advance.

Which part of it, the XLR or the 1/4"?

 

[John Stephen]

The 1/4-inch. I know the XLR part is mic-level. When I did a general web search on this, the AI thing that comes up said the 1/4-inch could accept line-level signals, but I couldn't find any other references to that, and who knows how the AI thing came up with that.

 

[agedhorse]

All of the AI 1/4" inputs I have seen are instrument level.

 

[John Stephen]

OK thanks, that's what I would have expected. That one reference I found kinda threw me, but instrument level seems logical.

 

[ardgedee]

Don't know if this helps but Gollihur Music has an archive of AI's manuals. The Series III manual for the Clarus says this: "The 1/4 inch input has a 1 megohm input impedance that is optimized to get the best sound from piezo pickups. The XLR input is a low impedance balanced input with sufficient gain to allow microphones to be plugged into it."

 

[roccobass]

Exactly what @ardgedee said!

Also, Gollihur used to be a main distributor for them. If you had some questions that weren't in the manual, maybe give them a call and ask for Mark. Ph: 856-292-3194

Enjoy your Clarus. I miss my Corus R.

 

[agedhorse]

Don't know if this helps but Gollihur Music has an archive of AI's manuals. The Series III manual for the Clarus says this: "The 1/4 inch input has a 1 megohm input impedance that is optimized to get the best sound from piezo pickups. The XLR input is a low impedance balanced input with sufficient gain to allow microphones to be plugged into it."

Impedance is unrelated to level.

 

[John Stephen]

Thanks all for your comments. Much appreciated. I found the manual online and I saw those quotes, but in the end I'm thinking @agedhorse has it. Nonetheless, I did shoot an email to Mark Gollihur to see what he said. I'll let you know if and when I hear back.

 

[Chris Wilke]

I have the contra series iii (combo version) -great little amp!

Why not use the effects return? I believe it will be post EQ, but it has level control.

 

[brianrost]

What's the line level device you want to plug into the Clarus? Does it have an output level control? If you can reduce the level enough, the 1/4" input might work OK.

If the device has an XLR out, you can buy inline pads to drop the level. Whirlwind's Imp Pad comes in 10, 20, 30, and 40dB attenuation versions. Sweetwater sells them for $34 each.

If the device only has a 1/4" out, a passive DI box with an input pad of 15dB or more would probably work to connect to the XLR input of the Clarus.

Check the manual or spec sheet for the device to determine what the max output levels are.

 

[John Stephen]

What's the line level device you want to plug into the Clarus? Does it have an output level control? If you can reduce the level enough, the 1/4" input might work OK.

If the device has an XLR out, you can buy inline pads to drop the level. Whirlwind's Imp Pad comes in 10, 20, 30, and 40dB attenuation versions. Sweetwater sells them for $34 each.

If the device only has a 1/4" out, a passive DI box with an input pad of 15dB or more would probably work to connect to the XLR input of the Clarus.

Check the manual or spec sheet for the device to determine what the max output levels are.

Thanks Brian. The device I want to plug in is a Red Panda Bit Mixer Mixer . It's only a 1/4 inch output jack, no XLR on this puppy. I did get it confirmed that the output is line level.

 

[brianrost]

John,

That Red Panda can be used for line levels, but it's really meant for guitar levels, or so it says in the description. Maximum output is unity gain, that means the knobs act as attenuators, there is no way to boost the input signal. Claiming it works with line levels simply means it shouldn't clip if the inputs are too hot, but I'd guess they are talking about -10 dB "consumer" line levels, not +4 dB "pro" line levels.

If you only plug guitar level signals into it, the Clarus will handle it just fine. If you should hear any preamp clipping, just use the knobs to lower the levels.

 

[John Stephen]

John,

That Red Panda can be used for line levels, but it's really meant for guitar levels, or so it says in the description. Maximum output is unity gain, that means the knobs act as attenuators, there is no way to boost the input signal. Claiming it works with line levels simply means it shouldn't clip if the inputs are too hot, but I'd guess they are talking about -10 dB "consumer" line levels, not +4 dB "pro" line levels.

If you only plug guitar level signals into it, the Clarus will handle it just fine. If you should hear any preamp clipping, just use the knobs to lower the levels.

VERY helpful, thanks Brian. That is good to know. I appreciate the technical insight on this, which I don't have.

 

[logdrum]

DO NOT PLUG a LINE LEVEL DI on the XLR, you will be in a lot of hurt even barely opening the gain will distort low bass signals

Line Level to the FX return only and start low on the level also

 

[John Stephen]

DO NOT PLUG a LINE LEVEL DI on the XLR, you will be in a lot of hurt even barely opening the gain will distort low bass signals

Line Level to the FX return only and start low on the level also

thanks @logdrum, I appreciate your thoughts on this. I don't have a DI. I have a small mixer, with a 1/4-inch jack for an output cord, and the output was described to me as line level. I would be inserting it into the 1/4 inch input jack on the Clarus amp. But you say I should only insert it into the FX Return?

EDIT: After reading your post, I looked back at the Clarus manual, and there is a sentence that says the FX return "can also be used as an auxiliary input for connecting other line level signals such as a CD player."

Thanks again. to you and everybody for your responses. I'll definitely post if I hear back from Mark Gollihur as well.

 

[logdrum]

thanks @logdrum, I appreciate your thoughts on this. I don't have a DI. I have a small mixer, with a 1/4-inch jack for an output cord, and the output was described to me as line level. I would be inserting it into the 1/4 inch input jack on the Clarus amp. But you say I should only insert it into the FX Return?

EDIT: After reading your post, I looked back at the Clarus manual, and there is a sentence that says the FX return "can also be used as an auxiliary input for connecting other line level signals such as a CD player."

Thanks again. to you and everybody for your responses. I'll definitely post if I hear back from Mark Gollihur as well.

The Clarus' Series III and early IV EQ I believe are optimized for upright bass -- The Series 4 plus which I also have have a low mid and high mid. I think on the 3 and early 4 the bass shelf frequency is set to 250 Hz and I think it needs to be higher for electric bass. I forgot the correct ideal frequencies plus the input impedance is not optimized for electric bass or you may have to set the HPF higher I believe

So in my case when I use the Clarus combo or the Focus R head (which have identical controls), when I use my preamp, I go directly to the FX return or if I go to the instrument in I really keep the gain down and keep the EQ flat or cut the bass some. I seem to have no issue with a Piezo direct, so I think flat is not flat but has some bake in bass boost to make Piezo sound full. If you have a mixer then that's probably line level

I do like the pre Series IV plus (2,3 and early 4) You have notch in addition to HPF and more effects and a an FX level, They lost all that in the 4 plus and moved many things to the back. Also the buttons feel a little flimsier as well on the 4 plus. These amps have a long life though. I've seen early series I still running.

 

[John Stephen]

Indeed, mine is 20 years old and still ticking. Thanks again for your insight into the Clarus, it's very helpful.

 

[brianrost]

So John you haven't told us what you will be plugging into that mixer in the first place.

From the AI Series III manual:

Bass Control Shelving type, ±15 dB at 60 Hz
Mid Control ±15 dB at 650 Hz
Treble Control Shelving type, ±25 dB at 10 kHz

Those are suitable for bass guitar or upright bass, although the treble is set pretty high.

 

[John Stephen]

I'll be plugging two instruments into the mixer -- a Fender Telecaster guitar and an acoustic guitar with a pickup attached to it. Other than this Red Panda mixer, I've also got a basic Morley A/B box that I could use too. No electronic issues there, it just passes the instruments' signals on to the amp. I've had the Clarus amp for about 20 years, back in my double-bass days.