effects loop idea

[loudthud]

No one can possibly answer your question without knowing the exact model of the DSP processor. Did it come with a manual? Got a schematic?

[daz]

No one can possibly answer your question without knowing the exact model of the DSP processor. Did it come with a manual? Got a schematic?

It's a boss VF-1 and if you want specs here they are... https://www.manualslib.com/manual/31...age=137#manual

[daz]

Thanks for going to the trouble Steve, but i figured out how to make it work with a feature of the DSP. Look at my post #15.

One solution might be to plug in a clean boost FX pedal between the Boss VF-1 output and the passive FX return jack. I put a BBE Boosta Grande into the FX loop of the Tech21 Trademark 10 I used for low volume informal jams awhile back (I used the clean Fender emulation mode which sounded like crap if you turned the Gain up any higher than 9:00 which kept the maximum output level much lower than that of the Marshall or Mesa Boogie modes.)


The Dumble ODS amps had a passive FX loop (see Exhibit A) but it was intended to be used with his tube-driven Dumbleator accessory (see Exhibit B.)


EXHIBIT A:


http://music-electronics-forum.com/a...p;d=1476146844





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EXHIBIT B:



http://music-electronics-forum.com/a...p;d=1476146844








Steve A.

[Steve A.]

Another solution?

One solution might be to plug in a clean boost FX pedal between the Boss VF-1 output and the passive FX return jack. I put a BBE Boosta Grande into the FX loop of the Tech21 Trademark 10 I used for low volume informal jams awhile back (I used the clean Fender emulation mode which sounded like crap if you turned the Gain up any higher than 9:00 which kept the maximum output level much lower than that of the Marshall or Mesa Boogie modes.)

The Dumble ODS amps had a passive FX loop (see Exhibit A) but it was intended to be used with his tube-driven Dumbleator accessory (see Exhibit B.)

EXHIBIT A:



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EXHIBIT B:







Steve Ahola

[daz]

I just replied to your post, but how the hell did my reply get BEFORE the post i was replying to?!!!! WTF???????????

[Steve A.]

...The unit is a DSP thats made to use as either a guitar processor or a line level processor. So while it has in and out jacks on the back, it also has a input on the front for hi impedance. It's labeled "guitar hi Z". I never used it in the past aside form some recording i did with it years ago because it has some amp models built in. Other then that i always used it as a line level effects. Now it works perfect and the input is perfectly adjustable and the master doesn't make it go from nothing to nuclear within 2 numbers on the master and the output is loud as hell !

Incredible !! so tell me....why does the pre PI master work perfectly in the guitar input? Wouldn't the signal coming out of it be much too hot for the processor's guitar input?

How do you have the -20/+4dB switch on the back set? On Page 4 of the manual it tells you to set the switch to -20dB when you have a guitar plugged into the input jack on the front panel. I would guess that by setting the switch to +4dB the front panel input can handle the hot signal from your amp...

FWIW a lot of FX processors have separate -20/+4dB switches for the input and the output while the Boss SE50/SE70/VF-1 processors have just a single switch for both which isn't quite as versatile.

BTW on Page 45 it shows you how to set the Global output level from 0 to 200%:



https://www.boss.info/us/support/by_...-ba9492428bf6/



Steve Ahola

[Steve A.]

I just replied to your post, but how the hell did my reply get BEFORE the post i was replying to?!!!! WTF???????????

It must be because we live in different time zones...

I was still adding the images to my earlier post and did not see your reply until I posted the final edit as a new post and deleted the original post.

Steve

[daz]

It must be because we live in different time zones...

I was still adding the images to my earlier post and did not see your reply until I posted the final edit as a new post and deleted the original post.

Steve

Ahhh, ok. So you DID post before me but deleted the original and reposted it with whatever changes you had made. Makes sense. I was beginning to think i was losing it. Still confused as to why it's back above my reply tho....

[daz]

It's on +4. If i use -20 the input gets pegged big time. On +4 i turn it all the way down and it's perfect right there. Thankfully, because if that was too hot i'd have to pad it down at the amp send. And yes, i know about the output level in the utility and use it all the time. I find i need to set it all the way to 200% to get the amp loud as hell but it gets there. Before i was using it as my master because if i turned the master up on the amp the input of the DSP would clip like crazy. Now it doesn't even clip with the amp all the way up. And before even on 200% the amp would not get to stage volume, not even close. The amp also sounds better too because there are no level mismatches. Before i was getting this hardness in the attack when i hit the strings hard, now it has give or compression in the attack.

How do you have the -20/+4dB switch on the back set? On Page 4 of the manual it tells you to set the switch to -20dB when you have a guitar plugged into the input jack on the front panel. I would guess that by setting the switch to +4dB the front panel input can handle the hot signal from your amp...

FWIW a lot of FX processors have separate -20/+4dB switches for the input and the output while the Boss SE50/SE70/VF-1 processors have just a single switch for both which isn't quite as versatile.

BTW on Page 45 it shows you how to set the Global output level from 0 to 200%:



https://www.boss.info/us/support/by_...-ba9492428bf6/

[ATTACH=CONFIG]41002[/ATTACH]

Steve Ahola

[Chuck H]

Hey daz,

Loops always seem to be overthought or underthought. It doesn't need to be complicated at all. I don't know the SS circuits well enough to give you an actual schematic, maybe someone else here will run with it. But this is the basic idea. And it will work.

[daz]

Hey daz,

Loops always seem to be overthought or underthought. It doesn't need to be complicated at all. I don't know the SS circuits well enough to give you an actual schematic, maybe someone else here will run with it. But this is the basic idea. And it will work.

Thanks for that Chuck, you're too kind. I will definately consider that if i get more input to where there are no questions as to how to go about it. But right now the chassis is back in the cab and it sounds so good i'm really afraid to touch it. But lets see how the thread evolves and maybe i will.

[daz]

How about this? https://store.metropoulos.net/produc...ss-fx-loop-kit
Anyone know if this is a good product? Seems to get good reviews and it would eliminate the trillion goofs i'd make building my own not to mention the uncountable posts from myself begging for help. Just want to be sure it's a good way to go before i jump in. Maybe there are better ones or better deals on a similar product out there?

Or how about this http://www.mojotone.com/Accessories_...ube-Amplifiers
This uses B= power, not sure about the metro but maybe this would be easier. Not sure how the metro one sources it's power.

[Chuck H]

That looks alright. Without a schematic I can only speculate that the designer got the output impedance matched up right so there won't be any small difference in tone/feel of the amp. That's probably the case. The site seems dedicated to keeping some authenticity. But you really could do it yourself for A LOT less than 85 bones plus shipping. Like ten bucks. We just need someone like Juan to pipe in with a circuit to replace my generic symbol in the above diagram. It would be a simpler circuit too. You really have no use for a -20dB option unless you plan to run foot pedals in the loop that won't take line level. Most pedals like EQ's, chorus, delay, etc. are fine at line level. It's things like distortion pedals that won't do line. And I can't think of any reason to run a distortion pedal in the loop. I would expect any signal processor to operate at line level, so what is the -20dB for?

[daz]

Well, if someone does i'll try it but if not this looks like my only option. Tho i=there IS one possible one. I tried this a couple weeks ago and it didn't work well but looking back i also didn't try any of the in./out options on the DSP so i'm going to try it again. That being inserting it at the treble pot out so the master has no effect on it. Last time it was a tone killer but maybe i can adjust the circuit for that or in the DSP. The metro loop is added in the same place, and considering my DSP is already a In/out circuit itself it should work if the level is enough at that point.

[Chuck H]

I'm going to tell you why that, or the signal from the master will never work. Your processor, and all other effects pedals and processors are simply not designed to handle as much signal as the an amp puts out between stages. Further, your processor, and all other effects pedals and processors are not capable of the output voltage necessary to duplicate source signal level. Further, the loop needs to operate at a fairly low impedance or even short cables will cause considerable signal loss in HF. That is why an effects loop has to be "padded" and "recovered" (some say buffered). An effects loop is "designed" to work compatibly with standardized effects units because such compatibility DOES NOT EXIST IN YOUR AMP without one. In other words, you will never find the magic source/return point in that amp where all you need to do is break the signal with a pair of jacks. Many have tried for decades and all have failed.