Tech Question re: Line Out Jack

[xring]

I did search, but not what I needed...
Is it safe to run the XLR out on my GK MB500 to my Crown XLS1500 Drivercore, and drive 2 - 4 ohm cabs via the Crown's Y input setting?
The minimum safe load on the GK is 4 ohms, but that is if I am using the power section to push cabs only? I don't think I'm "disconnecting" the power section, but will have no cabs hooked up to the GK obviously.
I don't want to harm my new GK, but it would be nice to drive my 4 ohm cabs.
Thanks.

[lug]

The XLR out of your GK has nothing to do with the output load of it's power section. It should work just fine. On the back of the GK you have a pre/post eq button. In this setup, make sure you put it in post, this allows you to use all the tone shaping of the GK.

[Downunderwonder]

Safe for amp, not safe for ears.

[ddhm]

One thing to note, amps don't like to be driven without a load on them. Your GK's power section might take a hit if there is no speaker connected to it. I would suggest using the GK's power section to drive one speaker and one channel of the Crown to power the other. Turn the other channel ALL the way down.

Another thing to note:If you are using an active bass (meaning it has an onboard pre amp), you could plug your bass straight into the signal input of the Crown. The pre on your bass outputs a line level signal and that's what your power amp wants to see for it's input. That's what I do and have for years. That way, you aren't pre amping an already pre-amped signal (thus adding noise and hiss).

You could also plug into your effects loop return on the GK and get the same effect.

I do understand that you just bought yer GK and would like to use it but it might not be needed. Your bass would have to do all the tone shaping in this case.

One last thing: If you are using cabs with multiple drivers in them, they could be rewired to be an 8 ohm load per box (perhaps) then they could be paralleled to bring them back to 4 ohms. Then you could just use your GK and leave the Crown @ home. WOOT for carrying less stuff

[xring]

So many thoughts here. Now I'm afraid to try it. I DON'T want to use my active basses alone as the only pre. I know for sure that on my equip, they do not drive the Crown to volume, and it doesn't sound great anyway.
My intention was to use the GK when I want to use one cab, then when I want to use both, I could send the pre signal to the Crown, and use both cabs.
What if I used either the 1/4" line out send, or the send from the effects loop to the Crown? Same problem?
I had the thought to short rack them both, and have my MXR M80 or SABBI as a back up pre.
The Crown is only around 7lbs. Nothing to carry.
I was going to get another MB500 so I could run both cabs, but the power amp idea was cheaper and a great idea or so I thought.
Any GK Reps availabe to answer this?
Thanks.

[ddhm]

You can't use the FX send without using the return to get the signal back to the power amp section of the GK.

The 1/4 line out might work though. The question then is if the line out is pre or post EQ.

[projectMalamute]

The GK will run fine with no load on the amp, you are getting bad information here.

Don't worry about it.

Line out -> Crown -> cabs.

Don't use the speaker outs on the GK.

[ddhm]

Originally Posted by projectMalamute

The GK will run fine with no load on the amp, you are getting bad information here.

Don't worry about it.

Line out -> Crown -> cabs.

Don't use the speaker outs on the GK.

Are you sure about that? I can't say for sure that the GK doesn't care if it has a load on it and it's better safe than sorry in the case of Xring's new amp. I would make a call to GK's tech support about that. It might run "fine" for a while and then die lol.I do however know that most power amps don't like to run without a load on them.

[projectMalamute]

Originally Posted by ddhm

Are you sure about that? I can't say for sure that the GK doesn't care if it has a load on it and it's better safe than sorry in the case of Xring's new amp. I would make a call to GK's tech support about that. It might run "fine" for a while and then die lol.I do however know that most power amps don't like to run without a load on them.

Yes, I am sure.

Almost all power amps could care less if they have a load on them.

The only amps that do care are those with an output transformer, which for all intents and purposes means tube amps.

[Smurf-o-Deth]

The manuals for the MB series amps even state unequivocally that they are safe with no load. You're fine.

[xring]

I guess I'm fine then. And happy!
Rule #1 for me? Read the manual. Duh.

[Bass_Pounder]

Originally Posted by ddhm

One thing to note, amps don't like to be driven without a load on them. Your GK's power section might take a hit if there is no speaker connected to it. I would suggest using the GK's power section to drive one speaker and one channel of the Crown to power the other. Turn the other channel ALL the way down.

Another thing to note:If you are using an active bass (meaning it has an onboard pre amp), you could plug your bass straight into the signal input of the Crown. The pre on your bass outputs a line level signal and that's what your power amp wants to see for it's input. That's what I do and have for years. That way, you aren't pre amping an already pre-amped signal (thus adding noise and hiss).

You could also plug into your effects loop return on the GK and get the same effect.

I do understand that you just bought yer GK and would like to use it but it might not be needed. Your bass would have to do all the tone shaping in this case.

One last thing: If you are using cabs with multiple drivers in them, they could be rewired to be an 8 ohm load per box (perhaps) then they could be paralleled to bring them back to 4 ohms. Then you could just use your GK and leave the Crown @ home. WOOT for carrying less stuff

Wow.........

All kinds of BAD info here.

Solid state amps CAN be run without a load on the output

A basses onboard pre (active pickups) *may* be hot enough to drive some power amps, but it is NOT intended to operate that way. For a power amp to be driven to it's full potential, you need a preamp that delivers line level signal. NOT an onboard pre that deleivers instrument level.

Lastly, you CANNOT re-wire ANY multi-driver 4 ohm cab to be an 8 ohm cab.

Originally Posted by ddhm

You can't use the FX send without using the return to get the signal back to the power amp section of the GK.

The 1/4 line out might work though. The question then is if the line out is pre or post EQ.

Also bad info

Using the send of an FX loop does NOT require you to also plug back into the return.

[xring]

[greenboy]

Jeez. Good thing people have stepped in with real info. ddhm, newbies should be very afraid of your posts. I'd be afraid I was going to cause problems for others if I just shot before actually taking aim ; }

[ddhm]

Originally Posted by Bass_Pounder

Wow.........

All kinds of BAD info here.

Solid state amps CAN be run without a load on the output

A basses onboard pre (active pickups) *may* be hot enough to drive some power amps, but it is NOT intended to operate that way. For a power amp to be driven to it's full potential, you need a preamp that delivers line level signal. NOT an onboard pre that deleivers instrument level.

Lastly, you CANNOT re-wire ANY multi-driver 4 ohm cab to be an 8 ohm cab.



Also bad info

Using the send of an FX loop does NOT require you to also plug back into the return.

It is a fact that some modern solid state amps do have output transformers (Nemesis, some class D's, ect.) and require a load. I'm not speaking in absolutes here and neither should you. Does a GK? Now that I've read the manual, I see that it can support a "no load" situation. It must not be one of the amps that require a load. My bad.

In talking about "bad" information: my earlier post said "Your GK's power section might take a hit if there is no speaker connected to it." Notice the word "might". Also notice that I suggested that he give the manufacturer a call or email about it. I did not have the manual for his amp, so I had no idea if it would be hurt or not. Is that really bad information? Really? It was intended to be safe information. I didn't want him to harm his amp and suggested that he be sure about what he does before doing it.

Not knowing which drivers and how many are in his (or her) box, I can't say that it could be. If you had a box with (4) 8ohm speakers, you could series #1&2 (for 16 ohms), series#3&4 (for 16 ohms) and parallel the two to get 8 ohms. Again, I don't know what drivers or box for that matter that X is using. Also, considering that he is using 2 cabs, he could get the combination of the 2 to his desired ohm load.

In the case of some fx loops, they are a break in the internal signal chain and DO require that the return be used. It is interrupting the signal chain before it goes to the power section. Is this the case with this GK? I guess that only a look at the schematic will tell.

In the case of an onboard pre: "may" is not an absolute and it works VERY well for me. Perhaps my pre is a bit hotter?

In any case, the information that I provided is not "bad"... it's situational. I suggested that he look into his situation and make an informed decision.

[Bass_Pounder]

Originally Posted by ddhm

It is a fact that some modern solid state amps do have output transformers (Nemesis, some class D's, ect.) and require a load. I'm not speaking in absolutes here and neither should you. Does a GK? Now that I've read the manual, I see that it can support a "no load" situation. It must not be one of the amps that require a load. My bad.

In talking about "bad" information: my earlier post said "Your GK's power section might take a hit if there is no speaker connected to it." Notice the word "might". Also notice that I suggested that he give the manufacturer a call or email about it. I did not have the manual for his amp, so I had no idea if it would be hurt or not. Is that really bad information? Really? It was intended to be safe information. I didn't want him to harm his amp and suggested that he be sure about what he does before doing it.

Not knowing which drivers and how many are in his (or her) box, I can't say that it could be. If you had a box with (4) 8ohm speakers, you could series #1&2 (for 16 ohms), series#3&4 (for 16 ohms) and parallel the two to get 8 ohms. Again, I don't know what drivers or box for that matter that X is using. Also, considering that he is using 2 cabs, he could get the combination of the 2 to his desired ohm load.

In the case of some fx loops, they are a break in the internal signal chain and DO require that the return be used. It is interrupting the signal chain before it goes to the power section. Is this the case with this GK? I guess that only a look at the schematic will tell.

In the case of an onboard pre: "may" is not an absolute and it works VERY well for me. Perhaps my pre is a bit hotter?

In any case, the information that I provided is not "bad"... it's situational. I suggested that he look into his situation and make an informed decision.

I would still say "BAD"

Some of what you mention as an excuse for your info is the exception - not the rule.

99% of solid state amps can run without a load on the output

Again, even if you do not know what cab or speakers he has - YOU CANNOT REWIRE A 4 OHM MULTI-DRIVER CAB TO 8 OHMS. Do the math, and prove me wrong.

As far as FX loops - again, prove me wrong. The "standard" option of slaving one amp off of another is to run a line from the send of one amp to the return of another amp. *IF* we were to believe your opinions, then that would not work at all would it ?? I have not seen an amp yet (in over 30 years playing) that *MUST* have the send/return loop completed for the amp to continue working. If you know of one, then again - it is the exception, not the rule.

[xring]

I'm just gonna say that I appreciate anyone who takes the time to try to help.
It's better to err on the safe side I agree.
I need 2 4 ohm cabs, so re-wiring was not an option. I couldn't interpret a schematic to save my life, so that's when I start asking questions.
I did finally see that a no load is ok, so I'll probably report how it goes. I'm curious to see if it sounds as good as my "actual" pre I've been using.
Thanks again to all.

[okcrum]

I haven't seen a modern solid state amp with an output autotransformer since MacIntosh. Class D amps have filters, not transformers, in the output. The Eden Nemesis series does not have output transformers. The DIY audio Nemesis series does, but they are relatively small amps.

Some more accurate info is here:

What Solid State Amps with Output Transformer do you know of? - diyAudio

OP, for the vast majority of bass amps, tube amps are the only ones not safe to run with no load. The caveat with solid state amps is that you do not want to run them with a lower impedance load than they are rated for. Don't run a 2 ohm load on an amp rated for 4, for example. It might work for a gig or two, but you'll pay later.

[greenboy]

Then there were those old Music Man hybrids, weren't there? No modern run-of-the-mill stuff is designed that way though.

[BassmanPaul]

Originally Posted by xring

I guess I'm fine then. And happy!
Rule #1 for me? Read the manual. Duh.

As always: RTFM. Read The F(of your choice) Manual!!!