Marshall head as preamp?

I have a Marshall JCM800 200W valve head but no speakers for it.

If I wanted to use it as a preamp, can I use it without speakers connected and just connect the headphones to line in/mic?

hey wolffy!

I suppose you are not going to plug the headphons INTO the line IN right??? that would let your amp try to use em as a microphone, which will not work...

If the top has a line OUT, than thats still not fit to serve a headphone, you would need a headphone preamp between the amp lineout and your headphones in that case.

Running the valve without any speakers attached is something I would not risk, the amp will have a lot of watts on the outputs meant for the speakers, and thats a serious risk for catching an electric stroke just by touching the empty plugs. If it has a switch to turn off the speaker cabinet, then thats fine, if it keeps the output "on fire", I wouldnt do it.
I'm no electrician btw, just telling you what I'd do :)

Hey Wolffy:)
Dicks right!, you cant risk using the Marshall head like that. I've got a TSL100 JCM2000 and its got a XLR DI type option to go into my mixing desk, but I must always hook this up to a 4x12 cab because of the "lode". You'll fry everthing and probably damage all your gear( and theres a risk to life).And the cab must be compatible with that kind of head.

Hope this helps!
Pico:)

+1 never under-estimate the electricity supplied by a good amp... dont get fried brothers!
(glad i noticed wolffy online today, so I guess he survived the experiemental phase)

Amp always need to have speaker load on them, or plug amp into a dummy load, like a ada monster cab, palmer or something similar.

Your amp might have efx loop out, or a line out, but still needs some type of load connected.


M

Thanks for all the replies - yeah, I borrowed a Marshall 4x12 stack and am using that for load. I found the DI, but I've got noisy volume pots, so I'm going to have to get some work done on it before I can use it to record. Ah well! :(

If you want to record your guitar parts on a Marshall or other amp that has a 50/100watt head into your mixing desk or interface!. This is what you need to do( basically we all know that these amps sound their best when CrankedUp to the max!:D)....So>
>firstly you need to buy/use a THD type hotplate 8ohm/16ohm(check your speaker cab 1st to match these ohm's ok!(there are other Hotplate types/makes on the market so look around)Basically you hook your head up to the hotplate and then run a line into your speaker cab.....what happens is you can put your amp head volume on high but adjust the power soak/brake volume on your hotplate( this becomes your Master Volume)......so you get nice tube sound but at bedroom/studio levels....Hughes & Kettner have this built into their tube-meister amps(redbox). I've got the 36 watt, and you can switch it down to 18 watt>5watt>1watt>"0"(zero)watt. In silent mode with Zero watt(power soak).... I still must be hooked up to a cab!, but with this feature I can get nice saturated sounds without annoying anyone...and plug straight into my interface>computer>mixer.
You'll find links on Youtube showing you the THD hotplate in action, and check out the Hughes&Kettner Tubemeister36 demo at the Musikmesse( With Rob Marchello)....I just put this info up because of Wolffy's question regarding this option!....don't want any of you people to get hurt/fried by using these type of Amps in the wrong way!:)

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Edited by incivanpico on August 31 2014 19:59

Thanks incivanpico. I didn't even know these devices existed so I'll have a look at them.

Yup, attenuator with a line out. I do it all the time. Run the speaker out from your amp to the speaker in on the attenuator. Run the line out from the attenuator into your interface and load a speaker impulse response in your DAW. I use two-notes wall of sound for that. I have a lot of vintage tube amps in my stash to pick from, it's fun.

[img]https://i.imgur.com/AbF1mRw.jpg[/img]

[img]https://i.imgur.com/TGKpP4B.jpg[/img]

[img]https://i.imgur.com/eAf3r36.jpg[/img]

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Edited by Riffraff on March 30 2021 02:24