ScottK
80 posts
May 08, 2017
7:32 PM
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When I was at this blues jam yesterday the a guitar player was pretty insistent that I need to be careful about my mic going directly to the amp. That I could run into a problem with my amp cause the signal was made for guitar. I tried to sound like I knew what was doing but then quickly realized he had a lot of wisdom and years more experience and let him tell me what he thought I should do.
I was set up as: My mic>cable>impedence adaptor>Boss DD3 delay> Amp
He thought that this way there could be issues with me going directly into my amp, especially with a delay pedal. He said I should have a pre-amp of some sort and an effects loop. He showed me his effects loop in the back of his amp. His was solid state and mine is tube.
So is this correct? or something to consider?
My amp: VHT SP6
My mic I was using: shure 545sd
I also have an AKAI DM13
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indigo
365 posts
May 08, 2017
8:52 PM
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I hope it's Ok 'cos i have been doing just that for years:^
The amp just amplifies what it gets and no Guitar pedal is going to cause any damage to a Guitar amp.
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SuperBee
4682 posts
May 08, 2017
8:53 PM
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I have no idea what he was talking about.
But the idea you shouldn't plug straight in; what should you do?
The mic, properly impedance-matched, will deliver a higher voltage signal on average than will a guitar.
With an amp set up for guitar this can be problematic, mainly 'problematic' will mean feedback.
One of the reasons the VHT is popular with harp players is that it's not so bad in this respect.
Many guitar amps have a lot of gain in the preamp. With harp it's better to have less gain, which will give you more control over your levels.
But by all accounts the VHT is not too bad in this respect. Some people put a lower gain tube in the preamp to make it more harp friendly. Won't make it louder but will maybe give you more useable volume
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SuperBee
4683 posts
May 08, 2017
8:57 PM
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Oh yeah I read again, now I see.
Yeah, some folks use a preamp but a volume control on your mic can also do the same job.. rest assured you won't harm your amp going straight in. There are more ways to kill a cat than just choking it with butter.
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MindTheGap
2248 posts
May 08, 2017
10:53 PM
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There's no definite right or wrong way to do it, and from what I can see most harp players do it your way. Maybe simply because the classic old tube harp amps don't have effects loops? That's a guess though - SuperBee?
If using an amp with effects loop, you can get different sounds by having the effects in different parts of the signal chain. E.g. if you generate distortion in the preamp section, that distorted signal will go through the delay so your echoes would be distorted too. Whereas with your set up your echoes, as they diminish, won't overdrive the amp.
Without having to rewire the amp, you could achieve a similar thing by putting a Harp Break or similar at the start of your effects chain.
But a typical way to use a delay with a harp is not long, spacey echoes, but a short single repeat to thicken up the sound. So the difference between direct vs effects loop isn't much in that case.
I guess a concern might be that your mic, with it's much stronger signal than a guitar, might overdrive your delay pedal. That could be a nasty, clipped sound rather than a nice tubey distortion. I think you'd hear that. In which case, again a Harp Break (or similar) in front would cure that. Generate the nice grit in the HB, and use it to bring the signal level down to NOT distort the delay pedal.
Last Edited by MindTheGap on May 09, 2017 12:19 AM
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ScottK
81 posts
May 09, 2017
4:48 AM
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Thanks everyone that's what I thought. Great info.
Do you think using my joyo American sound pedal would be useful in this mix for controlling my levels feedback etc? I'll mess around with it, but was mostly thinking I'd use it when directly going into a PA.
And another thought should I consider getting a feedback eliminator? If so, any reccomendations? The lone wolf mojo pad? Or would a VC be a better help? Eventually I'd like to have a VC or a mic with VC built in.
Last Edited by ScottK on May 09, 2017 4:54 AM
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Killa_Hertz
2355 posts
May 09, 2017
5:26 AM
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I have no idea what this guy is talking about. You ll be fine. MTG explained the advantage of an effects Loop, but it's not needed and for certain effects.. unwanted.
The joyo could actually be used to fight feedback. The only problem is .. I fund it robs a bit of tone. You can use it to dial back your signal a bit. It actually works similar to the "harp man" pedal. After all the harp man is a repurposed overdrive pedal. Mess around with different settings and see what you can get out of it.
I tried the harp shield, but didn't like it. I think if you put a lower gain tube in the preamp and get a VC you will be fine. Try using the joyo by following the instructions for the harp man on memphis minis wwvsite.
As far as VC ... I HIGHLY recommend Greg's inline VC. The problem with a mic with a built in vc is ... you have to put one on every mic. The inline you can switch to all of your mics.
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MindTheGap
2251 posts
May 09, 2017
9:57 AM
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I agree with all that.
Re those anti-feedback devices, I've not tried them but I did some investigation and was put right off. They are so expensive, but the benefits are not clear. There was a recent demo on the MF with a dB meter that showed tiny gains in available volume.
Killa has much more kit to try than I have, but it seems clear to me that a mic with a strong signal plus a VC gives you all the flexibility you need to get the right voltages into the amp to control feedback and give the sound you want.
The Mojo Pad does look like a useful fixed attenuator, but you can simply turn down the VC to get the same effect.
Last Edited by MindTheGap on May 09, 2017 10:04 AM
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Killa_Hertz
2359 posts
May 09, 2017
10:48 AM
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Yea, to be fair ... I don't play gigs. So I'm not limited to some tiny stage or some other unideal situation.
But I find that a lower gain tube in the preamp not only gives you a better tone, but also gives you a bit less feedback.
Then proper amp settings give you a bit more.
Then you get the rest from the VC.
There are people who say that you lose a bit of tone/volume just by running a vc. Which makes total sense, but ... I'm not sure that tiny extra boost in tone is worth not having the ultra convenient VC.
Now there are many pro players that don't use them Dennis G, Steve Guyger... tons of great players. I do think that you can get to a level that your mic handling skills can compensate for alot of these things. VC, feedback pedals, etc.
But i'm nowhere near there yet, so ...
And I suppose that's a whole different conversation.
P.S. I wanna say this and I'll never bring it up again. The mem mini thread was just me having a bit of fun. I exaggerate in the interest of humor and I guess it doesn't always translatell to text. I dont care what you play. Just as long as your happy with it.
Last Edited by Killa_Hertz on May 09, 2017 10:53 AM
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MindTheGap
2252 posts
May 09, 2017
11:58 AM
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Killa - everyone must surely be used to your hyperbolic writing style by know. I like it. We've all got our ranty subjects - mine is dodgy physics & electronics presented as fact :)
Actually you put out some useful factual info at the start of the MM thread. People can make their own judgement. I can't begin to understand the people issues around the MM, but the technical facts are interesting.
Last Edited by MindTheGap on May 09, 2017 12:03 PM
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Killa_Hertz
2360 posts
May 09, 2017
12:05 PM
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Good ... as long as yall get it. The rest can figure it out. Lol.
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ScottK
82 posts
May 09, 2017
8:03 PM
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Thanks for the info again all!
Killa- what lower gain tube do players use/ reccomend?
The info about the MM was interesting to me. It was in my potential amp list at first.
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Killa_Hertz
2362 posts
May 09, 2017
8:51 PM
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Scott if your amp runs a 12ax7 I would try a 5751 at first. That's the first step down. I would recommend a NOS tube. You could find a general Electric 5 Star for about $15. And it'll sound better than any new production tube.
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SuperBee
4689 posts
May 09, 2017
11:11 PM
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Funny you know the 1st time I saw the VHT was when the guy who used to work on my amps showed me. He was remarking on the price. Also on the shoddy build. This was before I ever dug into doing any work on amps and trying to understand what was what. I just took his word for it. He showed me photos of poor solder joints but said for under $250 it was no big deal, you'd just resolder
I got on here and was skeptical about the amp while everyone was busy lauding it as the best thing ever.
Time passed and the VHT seems to have continued to function. I waited for the reports of failure to start rolling in but so far they haven't.
Mod kits appeared, it was almost Valve Junior time all over again, only with a 10" speaker and fewer manufacturers design flaws.
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ScottK
84 posts
May 10, 2017
5:32 AM
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Thanks Killa, so the brand that comes up for the lowest cost (in a quick search- Im not ordering anything yet) is JJ. Are any brands better than others or is A NOS 5751 similar from anywhere?
Ya, the VHT is still the best sounding small amp I tried IMO And knowing that it's still going to be my playing that will really be the most important, but just the sound that comes out of the amp, tone kind of crunchy. I've only played around with it a handful of times and know I've got a lot to learn, but very happy I didn't spend a lot more money. Keep my options open for the future.
And Killa, like you wrote in another thread, I did hear a lot stuff regarding several other amps like: this is the best amp hands down etc....
I did come across one amp I really liked the sound a Peavy classic 30 used (12" speaker). at first I thought, ya this is the one for me, but then decided to do more research, and also if I was going to pay around $400 then i had to try other amps too, and decided to stay in the $200 range.
But a guitarist i just met and got together with to play who plays jazz blues happens to have the same amp (Peavy classic 30) so Ill be able to try that out to see what it may have been like.
Last Edited by ScottK on May 10, 2017 5:33 AM
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SuperBee
4692 posts
May 10, 2017
6:12 AM
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A friend of mine has a classic 30, also another local harp player (my first tutor) uses one.
I've done some work on my friend's.
Also saw Aki Kumar used one when he wS touring and picking up amps locally at the places he played.
My buddy actually just blew up the OT in his because he played with the speaker connection loose.
They are ok amps for sound and not too bad for harp though a bit high gain. Seem to take tube subs ok. Not nice to work on, rather cheaply constructed. But ok.
My mate had been having trouble, I saw the tube heaters weren't working, turned out to just be dirty sockets. He put a cannabis Rex speaker in it which he liked, but unfortunately failed to connect it securely. Not sure if he is getting it repaired or getting a new amp. Maybe he'll do both.
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Killa_Hertz
2366 posts
May 10, 2017
8:03 AM
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Superbee. Yea the solder jointo, board and parts aren't the best. I was also blown away by how crappy the cab is put together. But for $150 used and already modded .... can't really beat that.
When you start pushing into $400+ your talking a whole new list of great options. Anyhow.... I really liked mine and would buy another if it came at the right price.
Scott ... tubes. NOS = new old stock. Just incase you didn't know. So these are vintage tubes in new condition. There is absolutely a difference in quality from some NOS brands to other NOS brands. But even the low quality vintage tubes sound better than the newly manufacturer ones.
JJ tubes are ok. There are a couple new brands that are decent. But I still would go nos. Make sure it's tested. Matter of fact, let me know if you decide to go NOS .... I'll find you some good ones for a good price. I need a new 5751 anyways.
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ScottK
85 posts
May 10, 2017
4:06 PM
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Killa- thanks, yes I did not know what NOS meant. And ya I'll let you know when I'm ready. possibly soon, cause I am trying to learn how to handle the feedback. especially in a small space on a stage.
also I hope you named your dog cecil b. d'dog! ;)
Last Edited by ScottK on May 10, 2017 4:07 PM
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ScottK
88 posts
May 14, 2017
1:29 PM
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I was gonna start another thread about dealing with feedback but re-read this one which has a lot of info thanks.
So ya, after my second time using at a blues jam yesterday I know now that as is and my mics as is I can't go above 3 on the volume in a tight space at least. Was fine for a quieter bluesy jam but not when the band and other amps were louder. Which I knew was probably gonna be the case.
Before I just re-read this thread I googled and searched the forum, read more about squeal killer and other pedals etc..
So from the feedback (ya thats a pun) and suggestions from you guys my plan to start simple is:
swap in a NOS 5751 like Killa suggested (at the jam yesterday I was talking to a guy who asked me about my amp and I told him my plan to put in the different tube, we played together some and then he tells me that he actually builds and repairs amps (nice to know...)and has some NOS 5751 at his shop for not too much $. So I'm all set with that.
I'll mess around with my Joyo American sound to see how much more volume I can get out using that.
And possibly and very likey get a greg heumann VC.
So my cost should be the tube and the VC- and see how i can do with that.
I started possibly thinking (until I decided on my plan above)that If I had to get an anti FB pedal maybe id get a bulletini with VC instead but really I cant afford either right now and from what I'm finding out I don't need either just yet...
I chatted to another harp player that had an amp made by the guy I met, and he had a bulletini, said the VC on that helped him a lot with FB and he also was getting a VC to attach to his other mics. Unfortunately I couldn't stay to hear him play-had to pick my daughter up at college.
I should be able to get the tube soon, and if I don't before the next time I use it at this jam I'll opt to play on a quieter set or mic it.
Last Edited by ScottK on May 14, 2017 1:32 PM
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SuperBee
4707 posts
May 14, 2017
9:15 PM
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this morning i wrote an essay which was a distillation of everything i think i have learned about using small amps with harmonica.
fortunately for everyone who may have otherwise tried to read it, my phone battery gave up before i could post it.
ScottK i don't really know if you have some experience with amps already, for guitar.
the way i see it there are 2 main problems when using small amps for harp:
1)The audience/other people in the band cant hear you over all the other racket.
2)You can't hear yourself
the first problem is often easily overcome if there is a PA. Either mic the amp or use a direct line to the PA.
some would question why you are even bothering with an amp and suggest going direct to the PA, perhaps via some kind of tone-shaping device. the answer to that is of course that your amp IS the tone shaping device, and also that you want a monitor on stage which allows you to adjust what you're hearing without relying on someone at a mixing desk. This brings us to the second problem.
If you can't hear your amp, you can get some 'foldback' in the monitors. if your amp has a mic sitting in front of it, this will increase the potential for feedback. you have two mics on stage, both picking up your signal and potentially re-amplifying it. it requires good management.
if you can run a direct line from your amp to the PA the potential for feedback is less, but the sound quality may be less also.
and in both these situations you are still somewhat dependent on the mixer for being able to hear yourself.
thats ok if you have a competent, present, aware person on the desk, but it can be a bit hit or miss.
the best solution is to be able to hear your amp.
number 1 thing to do i believe is to get the amp up off the floor so the sound will travel past your ears. this makes a huge difference especially if you can get it up on a platform about hip or waist high.
this could be sufficient on its own.
another thing i strive for is to have nothing between me and my amp. i mean other amps, bodies, drums. you dont have to be directly in front of your amp, but you don't want something blocking your access or blocking the path of the soundwaves.
you may have to experiment a bit to find if feedback is specific to certain places or orientation on stage. i think i stand with my body between my mic and amp, or with the mic pointed 90 degrees from the speaker but just be aware of your position and your mic position re the speaker and sooner or later you'll automatically avoid feedback.
incidentally, this is one situation where i think the harp-shield pedal is potentially useful, in preventing 'accidental' feedback when moving around on stage.
if you can pay attention to those factors of amp position and your own postion relative to teh amp, you'll maximise the chance of hearing it on stage.
The other issue with using small guitar amps with harp is as mentioned earlier in the thread, these amps tend to have lots of preamp gain to amplify the relatively small signal from a guitar pickup.
this can cause problems when you play dynamically as the peaks can be above the feedback threshhold and this effectively limits the volume you can get from the amp as the adjustment on the volume is too tight.
there are 4 common approaches people take to address this.
remember though, there is a limit to how loud a small amp can get and sometimes even when you conquer the feedback problems you'll find the amp really doesn't get much louder but just more distorted. the point really is to find the sweet spot where the amp is sounding the way you like it. for me that is where the amp is full-toned but clean when i play normal/soft, and which will break up if i play louder or with acoustic textures. some amps deliver this over a range of volumes, others have a narrower range. if you are able to get the amp into distortion before feedback, chances are you are not going to get a lot more volume by turning it up. you may just get more distortion, which can be quite undesirable.
anyway, the 4 things
1)use a volume control on the mic
2)use some device to attenuate the signal on the way to the amp
3)install a preamp tube with a lower amplification factor
4)modify the preamp circuit
i think technically that's probably only 3 things as the tube is an integral part of the preamp circuit, but soldering 'seems' to be a more serious intervention as its more difficult to reverse and will void your warranty
Using a VC on the mic will allow you to open the amp volume up full if you want and hear the full character of your preamp. i know a former pro player here who swears by this approach, only uses small amps, turns them up full and uses a volume control. it definitely works for him.
Ive tried this. at home i really didn't get it. i was just as happy to have the mic up full and adjust the amp, but in a live situation i began to appreciate the idea. the amp was a given, and i was in control of the mic and could play as loud as i liked, as long as i didn't go past the feedback threshhold. with one of Greg Heumann's inline volume controls thats not likely to be a problem but i have had mics which were very easy to adjust involuntarily.
you may, or may not like the tonal 'colour' of your amp when its up full. the same principal can be applied across the entire range of the volume pot; there's no obligation to have the amp turned up 'all the way'.
plugging into a preamp or some other device to attenuate the signal is a similiar idea to turning the mic down, but usually allows some more flexibility in shaping the signal characteristics. its a popular choice, as indicated by the interaction with the guitarist decribed in the OP
"tubing down" is very popular and can be effective. the most common preamp tube is the 12ax7 and this has the highest amplification factor of the common noval tubes. tubes have 2 other 'constant' characteristics besides the amplification factor though, and these can influence the tonal character. so when you swap a tube to get lower amplification you may also get other less desirable side effects. this is why the change to a 5751 tube is often suggested as the 1st step, as this is the tube most similiar to a 12AX7 regarding the other constants. a 12AY7 is usually the next option, but there may be some significant tonal changes with this. not necessarily undesirable.
the 12AT7 and 12AU7 are somewhat more different and tend to make bigger tonal changes. many times a 12AU7 is claimed to sound dull, lifeless, dead, no sparkle, and i've heard 12AT7s criticised as 'harsh'. on the other hand, sometimes they sound wonderfully fine. it just depends on the amp circuit they are plugged into.
which leads us to option 4. this requires someone to knowledge of how the amp works. there are some well-established 'harp mods' for the vht. sometimes its as simple as clipping out a cathode bypass cap on the first stage of the preamp.
none of these things will make the amp louder, but they will potentially give you greater useable volume as they will make the amp easier to adjust for a greater overall volume.
if that's all sorted and the amp is performing well, probably the single change you can make which will have the most noticeable effect on the sound your amp makes, is to change the speaker. but that is a very personal and potentially expensive road and i have no advice on that.
and the other thing which maybe i should emphasize is that sometimes it doesn't matter what you do, the amp just isn't loud enough. in this case you need a bigger amp. some people start with a bassman, and then find they never use it. this is good, because after a few years they sell these very good unused amps for cheap.
so it seems after all i have written a lot more than anyone needs to read but there it is fwiw
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ScottK
89 posts
May 15, 2017
4:38 AM
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Superbee- thanks this is great! I'm going to read it again later and then again after that. Im definately going to get a 5751 and an inline VC from Greg.
And get my amp off the floor thanks!
And though I play guitar its always been acoustic and mostly solo, so the acoustic amp I used to use and going through my PA I haven't had issues. I've never had an electric guitar amp or an electric guitar...so ya this is my first of this type of amp experience.
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Fil
318 posts
May 17, 2017
6:40 AM
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SuperBee, keep on writing. Excellent post.
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Phil Pennington
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SuperBee
4708 posts
May 18, 2017
5:23 AM
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Cheers Fil, and ScottK.
There is certainly more can be said, and looking over that I see a few points which could be clearer but hopefully you can read between the lines some.
I'm not sure that reading about this stuff can really substitute for practical experience but it can provide some ideas to start experimenting with.
I've been reading these boards for about 8 years I think, and I've continued to learn things all that time. Including that I really didn't know what I thought I knew, plenty of times. There are a few different aspects to the subject.
On preamps, this is one reference which I think is worth a read if you have an interest in what's going on with tubes, how gain is only one part of the equation and why bias matters.
link
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Halffast
59 posts
May 18, 2017
6:39 AM
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ScottK ,
If you haven't done it already , you might want to remove the mesh screen from the back of your VHT . I , and many I know , have done this to make it easy to change/replace tubes without any dismantling of the amp ( although you need to do it once to do the mesh removal ).
Many will tell you the speaker needs replaced with a better one . Mine " warmed up " considerably after playing through it for a while and I see no reason to replace the speaker at all .
I was lucky enough to find a an assortment of NOS preamp tubes for sale as a lot on ebay . Tried them all and found one I preferred ( an obscure number old Sylvania tube , don't remember which # ). Sure did help with the volume/FB situation , as did putting a VC into my old Akai DM13 mics .
I really like the sound I get from this amp when running the mic through a delay ( slap back ) and a reverb pedal set to just " fatten " the tone . Of course the best sound is achieved just before the amp begins to feed back .
Have gigged many times with this setup . In smaller venues ( 50 people or less ), with an acoustic/electric guitarist , the volume of the amp has been sufficient . At larger venues and with bigger ( louder ) bands , I use a STAGG mic ( knockoff of a 57 ) set in the opening in the back of the amp and run it to the PA .
Haven't tried sitting the amp up on a stand yet .
Any amazing little rig for the money .
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ScottK
91 posts
May 18, 2017
4:40 PM
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Superbee- Thanks for the link and Ive read your previous post a few times very helpful.
Halffast- Im adding a new tube (NOS 5751) this weekend from an amp tech I met at a blues jam so I will think about keeping the mesh off when I do, thanks for the tip. Maybe I can keep my cord back there too. I actually did buy a used lil buddy speaker the other day, since id heard about them with this amp and one just happened to pop up. But I will keep using the stock speaker for awhile and then at some point compare them.
So you mic it from the back? I think I read about that, is this a common way to do it?
And I'll be getting a inline VC. I briefly considered getting a bulletini with VC or a ultimate with VC instead of an inline but I really should have an inline since though the only mic right now I'd use it with is a 545sd, I suspect I'll be using other low z mics like 57's etc.
And I'm gonna mess around using my Joyo American sound pedal like Killa wrote about similar to a Harp man pedal and I looked up how to do that on the memph mini website.
Last Edited by ScottK on May 18, 2017 4:47 PM
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arcticbreaze
6 posts
May 19, 2017
3:45 AM
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hi there, I struggled for a long time with the feed back issues. my five year experiments in tube amps finally paid off.
first I use a "Shaker" Mad Dog mic with built in volume control (really nice mic) I found any type of bullet mic was an invitation to feedback, too much gain.
second I ended up building my own harp amp, very loosely based on fender's 5E3 Deluxe I use 6sl7 octal valves about the same gain as a 12ay7 but better tone (subjective I know)then made channel 1 real low gain and fed it into channel 2 which is high gain, this gives me the same over all volume, but makes the mic less sensitive (I've been told by experts that it dose not work that way, but in real life....) output tubes are 6l6 into a clasictone 40watt OT I run this into a 2 X 12 cab with ET65's in it I can sit in front of it @ close to full 40 watts with out feedback. It sounds fantastic.
and when I go to the club to play.... I use the vocal mic thru the PA lol. sumtimes I take the shaker and swap the cord over.
thou I will take my rig if playing a full gig.
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