6505 + impulses

[Flow Of Time]

I know there are dozens of threads about that matter but I'm still unclear with some things...
I think of ordering a 6505, mainly to use it with irs and did a little research.
I read this thread and the guy mentioned that the preamp of the 6505 is kind of compensated and therefore muffled sounding :

Okay!! I realized that the name "Preamp Out" of the 6505 is a bit miss leading because it is actually not a line out of the preamp but a kind of compensated out for direct injecting the signal into a PA or a mixing console. I really wonder how the guys from this thread got the results. Has Peavey changed something in the circuit of the the amp?

Now I'm using the Send out of the effect loop and it sounds great:
Direct Signal of the SendOut
GuitarHackJJFred45_1
Mesa4x12SM57Pres8

Can anyone confirm this?

Also my interface (Line6 GX) doesn't have a line input, only guitar in. Could I use this to record the Preamp out/FX send signal anyway?

 

[nervirasme]

That's clearly a WRONG statement by zemes... I own 6505 head and I can assure you that the Preamp Out is a proper preamp-only signal. I really don't know what he did wrong but as soon you hear the sound coming from the Preamp Out you'll know that it's a clean and unprocessed preamp signal. I'm also using the 6505 with impulses. Take a look at one my threads where I was comparing it to the Revalver: http://www.ultimatemetal.com/forum/backline/714457-peavey-revalver-vs-real-6505-preamp-shootout.html

Good luck

 

[Flow Of Time]

Thanks for your answer, I was pretty irritated by zemes' post, since I never heard anything about a compensated out on a 6505 before
Could anyone answer the GX question?

 

[TheWinterSnow]

The preamp out is indeed a real preamp out. It won't be the best solution for getting good tones but it works. I have done comparison clips with the signal taken from the pre amp out and from the power amp out via the loadboxes I build and sell (comparison demo in my sig). I can tell you that a preamp out into impulses is going to be bright so I don't know what Zemes was doing wrong or if there was something wrong with his amp.

As for the GX, the preamp out is a high impedance relatively and you would realistically need a DI into a line in OR go form the preamp out straight into an instrument in. So it would be plenty ok if not better to go into the guitar in, just make sure you don't have any FX on in the chain from the interface to your daw unless you want to use line 6's cabs mics and preamp models to warm stuff up, but then again you could do that with POD Farm and would be able to use your own impulses.

 

[Flow Of Time]

Thanks for your detailed answer
I planned to buy a loadbox one day but I wanted to test the preamp out first (since I'm using impulses with imprinted poweramps most time anyway)
Maybe I'll get the 5153 mini, that would save me 200 bucks...

 

[TheWinterSnow]

Just a small heads up, the 5153 mini isn't going to be that much quieter than a 120 Watt amp so if you had plans on actually micing it up forget it, it will still be almost as loud. There are people that even use dummy loads to silently record 15W amps because even they are still too loud to crank properly. You will still need a load too and how much you want to pay for one depends on your options that you want like running through the preamp amp out or actually getting the signal post power amp.

 

[existencedenied]

you can use the preamp out of the 5153 mini without a cab plugged in. this has been confirmed by howard kaplan of EVH over at the gear page. You will still need a loadbox if you want poweramp saturation in your tone. Also, the mini sounds awesome at even bedroom volume, it has a very good master volume on it. It probably wouldn't sound very good mic'd at that level though.

 

[TheWinterSnow]

As an Electrical Engineer I can't understand why more amps aren't made so that you can get a preamp signal when the standby is on. Its not like the circuitry has to be changed except the preamps power being connected right before the bypass switch, not immediately after. At least some companies like Engl get the idea. And it is not like the small design modifications cause a difference in tone what so ever and proves no more of a safety threat to the amp then the norm. It is more of a tradition "thats how its always been done" kind of thing, not realizing amps need to adapt to newer technology. Silent home recording didn't exist when amps were first made, now almost every musician has a recording studio, and amps should adapt for that function. Fuck tradition if it impedes functionality of new technology.

you can use the preamp out of the 5153 mini without a cab plugged in.

This on the other hand I find a little hard to believe. Do you mean that you can get a signal out of the preamp when the standby is engaged therefore as long as you don't turn it off you don't need a cabinet? Sure that is understandable, but flat out using a tube power amp without a load unless is has built in default load is not.

 

[existencedenied]

as far as I understand, if you operate the amplifier with no speaker cable plugged in, the output is shorted.

http://www.thegearpage.net/board/showthread.php?p=13325418#post13325418

 

[TheWinterSnow]

I read that thread and they are either leaving out some information or are on crack. Shorting the power amp's signal to ground will cause the power tubes to over dissipate and redplate real quickly. They have to have a 8 or 16 ohm load shorting the signal to ground. That is a smart design though as I have that in my amp's design (whenever I get around to building it I don't know) but it is smart to have in case a cabinet is not plugged in you don't ruin your amp.

 

[Flow Of Time]

Ok.
I bought a 6505 today, but when I'm trying to record the preamp out directly into my GX there's a fucking loud hum comming through my monitors (even if monitoring is deactivated in my daw)...
And before someone asks : Yes I have a cab connected

Edit : I did some research in the manual and it says I should use a shielded instrument cable to record the preamp out...
Aren't all (decent quality) instrument cables shielded?

 

[SwambA]

This is how the rest of that conversation went


Quote:
Originally Posted by swamba
Sorry Howard, I don't mean to be a pain but could you tell me if its ok to leave my speaker cable unpluged from the speaker out of my 5150 50watt, there by shorting the output, for long periods of time? Will this hurt the amp or does shorting it out protect it from damage? I put a cable in the headphone out while still connected to the cab, but you can still hear a small amount of sound coming out of the speakers. If its not ok I will buy some sorta hotplate or dummy load. I'm am getting some really great results running staight out of the preamp, direct into a custom impules response, but would like the amp to be completly silent.

Thanks for your help Howard!!!!!


Quote:
Originally Posted by Howard Kaplan
If you are using the preamp output and are worried about the speaker load issue do the following. Put a jack or cable into the headphone output or connect a head set if you are using them to monitor the sound that is going into your 'impulse response' device. (I have no idea what this is. Is it for recording?). If the small amount of sound you hear from the speaker is bugging you, disconnect the speaker cable AT THE HEAD and the amp will them be driving a short. THIS IS OK even if the amp was not muted by a cable connected to the headphone jack. Shorting, the output is actually a better situation for the amp than leaving it open which will shorten the tube life.

In summary, disconnect the speaker cable at the head. Connect a dummy plug to the headphone jack or a headset. Connect you device to the preamp output and stop worrying. And if you forget to connect something to the headphone jack to mute the amp, do not worry as long as you do not have an open cable connected to the speaker outputs.

 

[Flow Of Time]

Hm, seems like I need a new Interface..
Since it isn't possible to record the preamp out with the post gain at zero I'll have to get a loadbox anyway.
I was thinking about the TT Tone Hound and this DI-Box.
Could anyone tell me if this DI-Box is good enough to "carry" the speaker out level (to the Tone Hound) and produce a good quality output signal?
Sorry if I sound like a noob, but that's what I am when it comes to tube amps

 

[TheWinterSnow]

In summary, disconnect the speaker cable at the head. Connect a dummy plug to the headphone jack or a headset. Connect you device to the preamp output and stop worrying. And if you forget to connect something to the headphone jack to mute the amp, do not worry as long as you do not have an open cable connected to the speaker outputs.

I would really not follow that advice what so ever. Simple ohms law will tell you that with real world ground resistances that it wouldn't take much of an output signal to over dissipate the tubes. Given a very conservative signal to ground resistance of typical wire at full power that little 50W amp could dissipate almost 700W. And if there was only a small signal from the phone jack being muted, it wouldn't take much to get the tubes over dissipating.

Could anyone tell me if this DI-Box is good enough to "carry" the speaker out level (to the Tone Hound) and produce a good quality output signal?
Sorry if I sound like a noob, but that's what I am when it comes to tube amps

A -30dB pad would be enough to handle speaker level but you would need a preamp as well if you want to be able to adjust tracking levels as the pan 01 does not have a level knob are any means of extra gain if the signal is too low.

You could also use a load and just go from the preamp out to the interface. However, you will still have some hum issues due to the ground loop that is being created by the amp being plugged into the interface. You would them need an isolating transformer between the preamp out and the interface. A DI would work but its not ideal. The pan 01 would work in that situation, and you could use the post gain on the amp to control the volume to the interface. You wouldn't be getting power amp coloration and therefore getting the tonehound would be one expensive load, although to my knowledge all loads are fairly expensive to begin with. Actually now that I just looked, most popular loadboxes aren't in production any more.

 

[Flow Of Time]

A -30dB pad would be enough to handle speaker level but you would need a preamp as well if you want to be able to adjust tracking levels as the pan 01 does not have a level knob are any means of extra gain if the signal is too low.

So the -30db switch has to be activated all the time?
The preamp thing shouldn't be a problem since I'll have to buy a new interface anyway (I'm going for one with built in pres of course)

I bought a 6505 today, but when I'm trying to record the preamp out directly into my GX there's a fucking loud hum comming through my monitors (even if monitoring is deactivated in my daw)...
And before someone asks : Yes I have a cab connected

Do you know what the problem could be here?
The humming is comming trough my monitors even if I don't have monitoring activated in my daw and the output signal on the gx is at 0.

 

[TheWinterSnow]

So the -30db switch has to be activated all the time?

Yup, speaker voltage is much larger than line level or preamp level.

Do you know what the problem could be here?
The humming is comming trough my monitors even if I don't have monitoring activated in my daw and the output signal on the gx is at 0.

Ground loop, you need ground isolation from the amp to the interface.

 

[Flow Of Time]

Yup, speaker voltage is much larger than line level or preamp level.

Does that mean I would fry the di box when disabling the switch (by accident).

Ground loop, you need ground isolation from the amp to the interface.

Shouldn't a shielded instrument cable kill the ground noise?
Apart from that I find it irritating that I hear the noise even if I'm not monitoring...
I know I sound completely dumb right know, sorry for that..

 

[TheWinterSnow]

Ground loop not ground noise. The earth connection of any device can only have one connection, since they are also tied to ground if a cable connects two devices with their own earth ground then each device has two paths, creating a ground loop, the ground (shield) has to be broken from the signal on one side, this is usual done via ground lift selection switch on a DI.

And as for frying the DI, it could at extreme levels, but your interface is more likely to go up in flames (literally) sooner.

 

[Flow Of Time]

Ahh, okay I think I understand now..
Thanks for your help and patience

 

[hsnyder]

As an Electrical Engineer I can't understand why more amps aren't made so that you can get a preamp signal when the standby is on.

Cause they're too lazy to design the power supply in such a way that the preamp voltage wont go through the roof from the decreased current draw of disconnecting the power tubes

Seriously I feel like some companies actually don't have any engineers at all - all they can do is copy schematics and solder some ribbon cable to a chinese PCB...