Get this Bullsh*t..

Pacomc79

nailz100 wrote:

So I can engage the boost straight from the clean channel and it'll jump to channel 3? How easy is it to change out the tubes in these bad boys? I will be playing alot of shows with it, so obviously I'll get a hard case with the head, but I also want to make sure that its not going to crap out on me all the time. How long to change the tubes? How many are there? If I have any service problems is there any change that someone here could fix it without me sending it all the way to Bogner?...it'll be used anyways (I guess thats something I should look into before I buy it)

I guess you've never actually physically seen one, it's very smartly laid out, much more space than in a marshall, there should be specs somewhere on the Bogner site, I know I've seen them. It's essentially an amp built by people who work on amps so they are by nature going to design it to be worked on easily if there's an issue. I'm not sure on the number of tubes I'll have to look again.


"Using the Shiva without the footswitch: Some people may not need to use their footswitch because they only need one channel to play thru. The Shiva defaults to the Clean channel with the Reverb on when no footswitch is plugged in, however to activate the High gain channel without using the footswitch you have two options: First option, plug in a "shorted" mono 1/4" instrument plug, this will give you the High gain channel with the Boost function engaged as well. Second option: plug in a "shorted" stereo 1/4" instrument plug, this will give you the High gain channel without the Boost function. Shorted means the tip and sleeve/ground are connected, using a "right-angle" plug is a good idea also since it has a low profile and will not protude out from the amp chassis very much. Also you can easily short the 1/4" plug internally, just solder a jumper between the two contacts."

. Tubes

EL34's should be only Svetlana or old stock Siemens/Telefunken/Mullard. Other brands may work but it's risky because of the high plate voltage we use. 6L6 should be Svetlana or Sovtec 5881, we prefer the first. For preamp tubes you could use everything from 12AX7, 7025, ECC82, ECC83, 12AXWB,1 2AX7WA, 12AT7 etc. Sovtek, EI, Electro Harmonix, Chinese, Tesla, GE, Philips, Telefunken, RCA etc. We prefer the Chinese 12AX7A's.

The Shiva has 6 preamp tubes (7 in reverb model) which do the following:

1st (closest to input jack) > Ch 1+2 > check that one if your amp gets noisy or microphonic.

2nd+3rd > Ch2 only

4th > one part (triode) Ch 1, second part for the loop send (affects both chanels)

5th > loop return (affects both chanels)

6th (second row in center of chassis) > phase inverter (affects both chanels)

7th (second row towards side of chassis) > reverb

Note: If you want to experiment with different tubes the first 3 tubes are the most noticeable ones, soundwise. The less gain the tube has and the earlier the tube is in the sound chain (1st, 2nd,..) the less noisy your amp is.

Make sure you turn your amp off when you switch tubes and be careful the tubes might be very hot!! Do not touch tube sockets with fingers? Even after turning your amp off and unplugging it from the power outlet there could be enough voltage stored in the capacitors to give you a lethal electrical shock.

you can see the tube layout on the bogner website, under the shiva. you can see how much space it gives the tubes to breath so even playing them loud they don't get too hot.

nailz100

Thanks Paco....you're right, no i've never seen one (only in pictures) Still didn't answer my question though if you can engage the boost straight from the clean channel? I know it doesn't boost the clean, but can you go straight from clean to channel 3? (as they call it)...or do you have to footswitch to channel 2 and then to the boost channel (I'll need the footswitch because I sing all the time)

Again, how easy is it to change these tubes out...say at a live show during set break? and how much do they cost? (I have never owned a tube amp before)

Of course I will not be able to afford this head for a little while now, but its good to know everything about it before I buy it....it is a big investment.

nailz100

Oh, also is there a led indicator on the amp to let you know what channel you are one (a feature I found very helpful on my Marshall)?

Pacomc79

nailz100 wrote:

Oh, also is there a led indicator on the amp to let you know what channel you are one (a feature I found very helpful on my Marshall)?

I think there is one on the footswitch, I can't remember about the front panel. I'll take note when I go check them out.

Pacomc79

nailz100 wrote:

Thanks Paco....you're right, no i've never seen one (only in pictures) Still didn't answer my question though if you can engage the boost straight from the clean channel? I know it doesn't boost the clean, but can you go straight from clean to channel 3? (as they call it)...or do you have to footswitch to channel 2 and then to the boost channel (I'll need the footswitch because I sing all the time)

Again, how easy is it to change these tubes out...say at a live show during set break? and how much do they cost? (I have never owned a tube amp before)

Of course I will not be able to afford this head for a little while now, but its good to know everything about it before I buy it....it is a big investment.

It looks fairly simple to me. There's plenty of room to get your hands in an out.

http://www.thetubestore.com can show you prices. They say only use the svetlana EL 34's due to the high plate voltages. Biasing is a whole other issue, but you'll probably be fine in a pinch, I think you are overestimating the fragility of the tubes, they last a good while, I'll find Sal Trentino's amp tips for you.

here it is. In case you're wondering yes, it's the same guy that built mike and stones amps for the last tour.

http://trentino.best.vwh.net/

nailz100

Cool, thanks. What is the difference between the pre-amp tubes and the power tubes (there are 7 power tubes on the shiva head?) how many pre-amp tubes. Sorry to ask man, but I know F*ck all about tube amps. Biasing is what exactly?

Pacomc79

nailz100 wrote:

Cool, thanks. What is the difference between the pre-amp tubes and the power tubes (there are 7 power tubes on the shiva head?) how many pre-amp tubes. Sorry to ask man, but I know F*ck all about tube amps. Biasing is what exactly?

no, there are 7 (in the reverb model) preamp tubes.

There are 2 power tubes for a total of 9 in the amplifier

9. What does it mean to "bias" the amplifier?
Just like the idle of your car may need adjusting when a major change is done to the engine, new power tubes need their idle (the "bias") adjusted to make sure the amp sounds as good as possible. Some amps do this automatically, but many do not - particularly in the world of guitar amps. Many tube amp owners are unaware of this simple regular service for their amp that will keep it sounding it's absolute best. The bias methods of amplifiers fall into several basic categories:
- fixed bias amplifiers
- cathode bias amplifiers
- adjustable bias amplifiers.
Each of these types is unique. Fixed bias amplifiers CAN'T be biased. These amps (for example, some Fender and Mesa Boogie models) are designed to run with tubes that have a specific current draw (see question 4) and should only use tubes that fall within a certain range. Fortunately, these amps are usually pretty forgiving and will work well with a pretty wide range of tubes. For the best results, specify the make and model of your amp in the "Comments" of your order and we will make sure you get the best tubes for your amp.
Cathode bias amplifiers shouldn't require any adjustments and will work with a wide range of tube plate currents, as the circuit is "self adjusting".
For adjustable bias amplifiers, the amp should be biased by a tech with experience with this procedure. It's not difficult, it doesn't take long, but if you don't know what you're doing you may hurt yourself (amps can give lethal electric shocks even when unplugged, and NO, we're not just saying that to scare you). Also, your amp may sound horrible or cause undue wear and tear on the tubes or power supply. Until you learn how to do it correctly by yourself, it's best to pay a technician a few dollars to do it for you.



Read everything here http://www.thetubestore.com/powertubeinfo.html

mccreadyisgod

nailz100 wrote:

Cool, thanks. What is the difference between the pre-amp tubes and the power tubes (there are 7 power tubes on the shiva head?) how many pre-amp tubes. Sorry to ask man, but I know F*ck all about tube amps. Biasing is what exactly?

Biasing is adjusting the plate voltage fed to the power tubes. If you under-feed them, they'll sag and fail early... if you feed them too much, they'll pop, and maybe take half your amp with them.

If you gig a lot, you'll probably be replacing the power tubes every 9-12 months. I'd always carry around a matched pair of power tubes, two preamp tubes, and a fuse anyways. You can actually buy a matched quartet of power tubes, and only use two at a time. Your preamp tubes might need swapping with the power tubes, but I generally replace preamp tubes every other time.

Preamp tubes are what take your guitar's signal at the beginning and pre-amplify and manipulate the sound. When the signal leaves the preamp section, it would barely drive a small set of headphones, let alone a 4x12" speaker cabinet, so they have big power tubes that amplify that signal enough to drive speakers. Preamp tubes operate on millivolt signals, power tubes operate on volt signals. That's kind of a rudimentary description, but it'll get you started.

Hey, Paco, check and see how easy it is to access the tubes... will he need to carry a screwdriver around to get a panel off?

I can't help you any on the footswitch question... but that's why I use single-channel amps and tubescreamers.

nailz100

Thanks for the info MIG. So you figure changing out the pre-amp tubes (7 of them) every six months or so and the power tubes (2 of them) about once every year? I could see how a tube amp could be pricy if your blowing pre-amp tubes all the time.

Pacomc79

nailz100 wrote:

Thanks for the info MIG. So you figure changing out the pre-amp tubes (7 of them) every six months or so and the power tubes (2 of them) about once every year? I could see how a tube amp could be pricy if your blowing pre-amp tubes all the time.

no, power tubes once a year, preamps maybe once every 2 years. It's not as bad as you think.

nailz100

K Thanks, Let me know what you think when you try one of these bad boys out. Tell me how much drive you can get through er'

Pacomc79

nailz100 wrote:

K Thanks, Let me know what you think when you try one of these bad boys out. Tell me how much drive you can get through er'

K, I'm going now. I'll post info later. I've got to get some strings anyway.

mccreadyisgod

nailz100 wrote:

Thanks for the info MIG. So you figure changing out the pre-amp tubes (7 of them) every six months or so and the power tubes (2 of them) about once every year? I could see how a tube amp could be pricy if your blowing pre-amp tubes all the time.

Paco got it... you took it backwards. Power tubes should run you about $25-30 a pair (I'd buy a quartet for $45-60) and preamp tubes will run about $6-15 apiece, depending on brand. I prefer Electro Harmonix for preamp tubes, they're about $10 apiece.

So, every year it's $30, and every other year it's $100.

Now, to flip-flop on my posts in other threads...

It would be a really good idea to have that amp biased when you swap tubes. My recommendation is to get matched quartets of power tubes, so that you can switch the power tubes once without biasing, and get it biased every two years (most likely when you are replacing the preamp tubes). In other words, bias it before putting in the first two tubes from the quartet, then you can replace with the other two from the quartet without needing it biased. And definitely get it biased the first time you replace the tubes. Bogners are great amps, but they're an amp guru's amp, so they're supposed to get regular care and feeding. And for that kind of investment, it's worth it to maintain it right. Besides, if I remember right, Bogner has some wicked high-voltage plate currents, so you'll want to check it.

Pacomc79

nailz100 wrote:

K Thanks, Let me know what you think when you try one of these bad boys out. Tell me how much drive you can get through er'

ok man, I'm back from the shop. Yes, it's got an indicator for the lead channel, on the amp and the footswitch. Boost is only on the lead channel and yes you can leave it on ready to go when you switch channels. Reverb is tube driven, full rich and glorious, which is pretty much how the clean goes. The clean also has a master volume to take you from completely clean to Hiwatt crunchy clean type tone. The lead channel takes you from where the first one leaves off all the way up to high gain rock lead but not so over the top that note definition is lost. The test guitar was a tom anderson with both single coils and a humbucker and yes they both play well.

The lead channel is very marshally but more dynamic with more balls, personally I doubt you'll need a Fulldrive to achieve what you're looking for but it does give you more and more of what's there, though I'd probably just go with some kind of clean boost, but it's not that necessary. With only 2 EL 34's I tend to think 80 watts a bit of an overstatement, even at high plate voltages I tend to doubt it's actually pushing that much power RMS, but don't think anything of it, you won't need more than it's got and it's more than enough for rich full tone at any volume level. More than enough to push 2 4x12 cabs should you choose to.

Unfortunately any repair save fuses and tubes is going to have to go to Bogner, they are extremely picky about people poking about in thier amplifiers aparently and unauthorized work voids the warranty.

Tubes are fairly simple to replace though it's a 10 min operation or so, you have to remove the back panel to get to everything but there's plenty of room for your hands.

The amp is as advertised and the soundclips posted are accurate.

nailz100

Now when you are talking about biasing the amp, you are talking about taking it into a shop rather than doing it myself right? The whole concept of biasing still has me a little confused. Paco you said for any repairs you have to send it to bogner right?

Thanks for checking into that for me Paco. Thats very cool that theres a LED indicator on the amp and the footswitch. I also like the fact that you can leave the boost on when you switch channels....that sounds awesome, apparently with the boost on it sounds much better than just channel 2 alone...thats what I read on Harmony central anyways. Hopefully you can adjust the gain/ master on the clean so that there is not too much jump in volume going from clean to distortion with the boost on. So you think the amps got enough distortion without the fulltone eh?....thats good to know. I guess I could always buy the head first and then get a fulltone if I can't get enough drive out of it.

As far as warranty goes for repairs, it really wouldn't apply to me, since I am going to end up saving over a grand by buying me used on E-bay...

Do you need a phillips screwdriver to remove the back panel to change the tubes out? When you replace tubes, do you usually replace the whole set (of 7) or just the one that you think is damaged?

You used just the Shiva EL34 head right? What type of cab/cabs did you plug into?

Pacomc79

nailz100 wrote:

Now when you are talking about biasing the amp, you are talking about taking it into a shop rather than doing it myself right? The whole concept of biasing still has me a little confused. Paco you said for any repairs you have to send it to bogner right?

Thanks for checking into that for me Paco. Thats very cool that theres a LED indicator on the amp and the footswitch. I also like the fact that you can leave the boost on when you switch channels....that sounds awesome, apparently with the boost on it sounds much better than just channel 2 alone...thats what I read on Harmony central anyways. Hopefully you can adjust the gain/ master on the clean so that there is not too much jump in volume going from clean to distortion with the boost on. So you think the amps got enough distortion without the fulltone eh?....thats good to know. I guess I could always buy the head first and then get a fulltone if I can't get enough drive out of it.

As far as warranty goes for repairs, it really wouldn't apply to me, since I am going to end up saving over a grand by buying me used on E-bay...

Do you need a phillips screwdriver to remove the back panel to change the tubes out? When you replace tubes, do you usually replace the whole set (of 7) or just the one that you think is damaged?

You used just the Shiva EL34 head right? What type of cab/cabs did you plug into?

Biasing is not all that difficult to do you just have to know how to do it. check out the meters here at http://www.webervst.com

When you replace tubes at a gig, you only replace the problem tubes, usually that's on of the preamp tubes V1 V2 V3 or one of the Power tubes.

This amp has 3 gain stages so there's plenty on hand and yes, you'll be able to find a happy medium of volume between the 2 channels.

you need a phillips screwdriver wouldn't hurt to bring an electric drill with you to the gig for speed purposes.

The Shiva head was plugged into what was available...a crappy old Fender 4x12. yeah, it sounded fantastic even through that cab. No worries.


The weber Bias rite. http://www.webervst.com/bias.html

nailz100

I appreciate you checking that Shiva head out for me...I really wish I could try one out as well. That biasing still has me really confused, but I guess I have a while to look into it, since its going to take me awhile to afford this amp. Thanks for all your info guys.

nailz100

Oh, any suggestions on a good cab to go with the Shiva EL34. I was thinking a 2 X 12 is probably the way I'm going to go, just for easy of transport, sound and room.

I was looking at the bogner oversize 2 X 12, maybe a Mesa? My plan is to save up enough to buy the head and the cab at the same time.

must be nice to drive 10 minutes and try one out Paco......*cough* fucker...hahaha

Thanks again

Pacomc79

nailz100 wrote:

Oh, any suggestions on a good cab to go with the Shiva EL34. I was thinking a 2 X 12 is probably the way I'm going to go, just for easy of transport, sound and room.

I was looking at the bogner oversize 2 X 12, maybe a Mesa? My plan is to save up enough to buy the head and the cab at the same time.

must be nice to drive 10 minutes and try one out Paco......*cough* fucker...hahaha

Thanks again

Yeah the bogner cab would be fine but you'll likely be ok with whatever you choose as long as the ohm's match up.

Biasing is simple, think of it like ignition in your car. if too much or too little power goes into your spark plug it burns out or dosen't fire right? same deal here. Biasing is just tuning the amp to the tube. Think of it as a tune up for your automobile.

nailz100

What kind of equipment do you need to bias the head yourself?

The bogner cabs are a bit more expensive, but might be worth it.