want to add direct line out to new amp

[palomino48]

Wanting to add a direct line out to a new small amp I'm about to buy - Roland Street Cube (monitor wedge-style). Will be using this amp primarily in church, hence small size & power. Am playing thru monitors presently, unsatisfactory - no control over stage volume, tone or effects. Have been told this is a good amp for what it is, size and power wise (no place nearby sells it, so can't try one out - buying from Sweetwater online, or some other such place).

Back to business. Amp has no direct line out, nor an effects in/out. Cannot allow speakers to be disabled, would defeat purpose of amp. So can't plug into headphone jack. Also, would like tap to be post onboard electronics effects. Figuring to open amp up, install a jack on back and tap either the headphone jack or speakers themselves. Have done minor repairs on amps before, never tried this. Would appreciate some insight from someone who has. Thanks!

[lunaalta]

Hi palomino48. Welcome to the nutz house!

I wouldn't tap from the speaker lines, if I were you. Not the best place.

The headphone signal would work, but you will have to be careful setting your signal levels, so as not to get too much of a distorted signal.
If you won't be using headphones, you could swap out the socket for a non switched one, which would save you from having cables or extra sockets. Maybe there is a way to control the level of the 'phones' out without affecting the amp level, but I can't help you with that, way over my head. Others here could probably improve on my suggestions, I'm sure someone will chime in soon.

Again, welcome to guitarnuts2.

[sumgai]

pal,

lunie said it best, just replace the headphone jack with a non-switching one. After all, in most cases the Line Out and the Headphone levels are near enough to the same thing - witness the vast majority of computers you've ever owned - how many output jacks were there? For 99.9% of all tasks, that one single jack can do both jobs.

As an alternative, you might consider simply soldering a jumper across the switching action so that the signal then goes both out the jack and on to the speakers. But note that the switching action takes place only on the speaker lead, and not on the low-level signal headed out of the jack - the two signals are isolated electrically, but they are physically close to each other. Be sure that in either case (swap out or shunting), you do not accidentally confuse the two signal paths, or else you'll find yourself with a handful of smoking components - and no warranty coverage!

Good luck!

HTH



Oh, and like the man said:

Hi, and to the NutzHouse!






sumgai

[palomino48]

I appreciate the two replies so far. Valid ideas, and just what I'm after. One other thing (and maybe I'm reaching for the stars here), I'd like to retain all of amp's present features, if possible. In other words, I'd prefer that no mods I make will delete use of headphone jack (muting speakers), and certainly don't want anything to affect speakers output or performance. I almost have it visualized in my mind how to approach the rewire and jack addition, tapped off of the headphone jack. Am just fuzzy enough about it at this point as to be patiently waiting for more input from you guys (or gals). Plus, I haven't bought the amp yet. There IS that....

And thanks to both for the welcome!

[JohnH]

A likley place is to take a connection from the hot outer lug of the master volume. Probably, the main emulation is before that, and you can still turn up the amp volume while keeping DI out level constant to a mixer.

[lunaalta]

A likley place is to take a connection from the hot outer lug of the master volume. Probably, the main emulation is before that, and you can still turn up the amp volume while keeping DI out level constant to a mixer.

A haaa. That's the suggestion I was looking for but couldn't find....

[JohnH]

Apr 21, 2013 4:10:44 GMT -5 lunaalta said:

A likley place is to take a connection from the hot outer lug of the master volume. Probably, the main emulation is before that, and you can still turn up the amp volume while keeping DI out level constant to a mixer.

A haaa. That's the suggestion I was looking for but couldn't find....

One rider to it. If the object is to go into a mixer line-in for the FOH mix, then the new DI out may need to have a fairly low output impedance, of the order of no more than say 10k. A buffer may be needed so the volume pot is not loaded too much . But as a stand-in, short or long term, a switched-off non-tru-bypass guitar pedal (eg Boss) will have a high impedamve input to connect to the amp volume pot, and a low impedance output that will drive a mixer.

If that all works, and you want to not need a pedal, and maybe you need a level control for your DI, a module such as this could help:

Active volume module
J

[palomino48]

Many thanks for the several points brought up by all who responded. It gives me some good items to consider. Still haven't bought amp yet - $$$. But hope to soon. Will keep all posted on the direction in which I choose to go, and how it turns out. And of course, am still ready to entertain any new ideas besides the good ones already posted.

[palomino48]

Incidentally, I got a kick out of the "descriptive" above my username at the left - "Amateur Solder Flinger". I used to teach "High Reliability Soldering to NASA Standards". Was a long time ago. But this was good for a grin.

[daddyloops]

hi all here is a video i made of me modding my roland street cube

pretty simple stuff - yielded god results, headphone level is per normal and speaker level per normal

hope it helps

[JFrankParnell]

That's cool, man. Just for fun, here's a mod I did with a Roland Cube and a Pignose Hog:
radiokdug.com/2012/12/pignose-roland-frankenhog/

[swingarm]

edited post the one i posted was for a tube amp sorry

[workman]

I know this is way late but it may help others.

I took the signal from the speakers (in stereo) and bought a High Level (speaker) to Line level converter and an output jack in the back of the Cube. The brand name is Response (about $15 from Jaycar in Australia). It works a treat. My Vocal/Guitar mix goes to the mixer/front of house as I set it & I only require 1 input instead of 2 into the desk. It leaves the headphone functionality intact. (as does daddyloops mod also). I have pictures but they are too big for guitarnutz2.

[newey]

Workman-

Hello and Welcome to G-Nutz2!

I have pictures but they are too big for guitarnutz2.

Not sure what you mean by "too big". If you are trying to attach the pix to a post, there is a file size limit. But the best way to post pix in the body of a post is by linking to the pix from a web photo hosting service like Photobucket or Imageshack.

If you mean that the photos are physically too big, you can downsize them before posting . . .

[ashcatlt]

Of course, your DI won't work with headphones plugged in. Maybe not an issue for the ways you plan to use the thing.

Realize that this converter box is almost certainly just a handful of resistors set up as a pair of simple voltage dividers. I know I'm late to the party, but you could have bought like a dual gang pot and maybe a couple resistors and done the same thing, but with inependent volume control and a bit cheaper.

You can also use a passive DI for this. Those with -10/-20db pad switches are specifically designed for that kind of thing. Very convenient if you have a stack, but some combos actually have a jack with their speakers plugged into it, and others with parallel speaker jacks can work for that, too. Some Ext Spkr jacks defeat the internal speakers, so you'd have to rewire it or actually run an external speaker. Tube amps don't love driving a light load, so you don't want to run the DI without a speaker. It's not a power soak.

With any of these resistive pads when there is a speaker, though, the amp's response to the speaker's inductance will be reflected on the DI out. Hack in an LPF for "speaker simulation...

But in this particular solid state emulated amplifier, I probably would have taken signal from the top of the Master like John said.