Custom Tube Amp, How Much Power?

[72LML]

First a disclaimer, I'm new to tube amps so if I say anything dumb please forgive me. OK now to the questions.

The lead guitarist in our band builds custom low watt (1-5 watts) tube amps, (http://www.facebook.com/RoctalAmps), and has offered to build me a custom bass tube amp as long as I pay for the parts and build the chassis. I know building a bass amp is going to be somewhat different form building a guitar amp but I’m confident that he’ll come up with something decent.

The question I have how much power should I go for? He basically offered me this:

125 - 175 watts for $300 - $350 in parts
or
225 - 300 watts for $400 - $450 in parts

Do I really need the extra power? Right now I’m just playing at church and some outside gigs, no big venues by any means. And of course with the extra power comes extra weight. Not sure how much I want to lug around and extra 10 – 15lbs if I don’t have to.

On the other hand if we’re going to go through the hassle of building one should we just go all out and build something that will have plenty of power? In all reality what kind of gig/venue would I actually need 300 watts for?

Assuming that he knows what he's doing do those prices seem accurate/fair?

[KramerBassFan]

I'm curious - where can your guitarist get parts to build a 300w tube amp for 400-$450?

But, i'd say the 225w.

[acubass]

I would go the 125-175 watt route. My 100w V4BH is just about perfect. The extra 25 watts may give just slightly more headroom.

[72LML]

I'm not sure where he's getting the parts from but I do know he's got some tubes and other parts lying around. So maybe he's not factoring those in to the cost. All I know is that's the prices he gave me.

[Deluge Of Sound]

Depends on how much clean headroom you want.

Also, if you don't mind me asking, what's he using as the basis for his builds?

Oh, for the record, I'd go with 175 watts with an oversized transformer (for bass response )

[72LML]

Deluge,

I'll have to get back to you as to what he bassing the build off of. I know that we've talked about the 300 watt Ampeg SVT heads and he did snag a transformer for a 300watt Ampeg to use for the build.

[Deluge Of Sound]

Fair enough. I was just curious on the tone stack/preamp design.

The initial questions I have about wattage in regards to the design:
Is this going to have a master volume?
Do you care about power-tube overdrive?
(repeatHow much clean headroom do you want?

[72LML]

It is going to have a gain and master volume along with the basic tone controls and a standby switch.

I do want some overdrive but not full on distortion. I like some "dirt" in my tone.

As for how much headroom I'm not really sure. I'm assuming that means how much clean tone you can get out of it (volume or power wise) before it starts to clip? (Remember I'm a newbie to tube amps)

[will33]

Originally Posted by 72LML

Right now I’m just playing at church and some outside gigs, no big venues by any means.

Bit of a conundrum here, church buildings have natural reverberation and sound great with un-mic'ed voices and little amplification, bass keeping up with the organs own internal amps, speakers, etc. Basically a small bass amp can sound huge in a nice church, outdoors presents the opposite problem. The lack of walls, re-enforcements, etc. means more speakers/more power to reach the same level. It can be humbling sometimes but lets you know just what you really have (or don't have). Also lets you know real quick whether or not your band is tight, everybody is so isolated, if you don't have your !@#$ together, it shows.

[will33]

To bring it back on topic, I'd be split between the 150+ watt small version and the 225-250 watt big version favoring the smaller of the big version just to allow for growth. But then again, I like the "warm but clean" fat thump tube sounds. Getting a little grit or distortion when I want it by digging into the strings or opening up a volume knob when I want to is cool but I don't want to have to deal with that just to get loud enough.

[edbass]

Originally Posted by KramerBassFan

I'm curious - where can your guitarist get parts to build a 300w tube amp for 400-$450?

Good question. The transformers alone could easily be almost twice that much.
72LML, ask your guitar player where he's getting the iron. If there is a low cost source out there you should share!

[Deluge Of Sound]

Originally Posted by 72LML

It is going to have a gain and master volume along with the basic tone controls and a standby switch.

I do want some overdrive but not full on distortion. I like some "dirt" in my tone.

As for how much headroom I'm not really sure. I'm assuming that means how much clean tone you can get out of it (volume or power wise) before it starts to clip? (Remember I'm a newbie to tube amps)

You're exactly right on the headroom bit. You'll have a much easier time trying to run, say, a 100-watt tube head into overdrive than you will a 300-watt head.

In my case, for example, I like power-tube distortion, so I run either a 100 watt or a 120 watt head. The advantage to tubes here is that you can get a lot of mileage of of your playing dynamics and attack--the tube "sweet spot," where digging it gives you a distorted tone and backing off lets you play clean.

Are you planning on running any overdrive/distortion pedals with this rig?

[T-Bird]

Hi.

Awesome price, congrats.

If he already has a 300W OT intended for bass use, ie fs=40Hz or thereabouts, I'd go for the 300W route.

Why?

With lower wattage output section, the transformer saturation is gone anyway, so the OT compression is lost, resulting a very little tone coloration from the OT. It's also easy enough to put 1/3, 2/3 & 3/3 power reducing switches to the PP pairs (thinking about 6 power tube terms), so lower wattages are there if needed.

Most odf the weight is in the OT and the PT, so if he's using that OT he has, the final weight is about the same regardless of the PT. Enough handles in the right spots makes even the heaviest of equipment easily manageable.

Even if it pumps up the parts count and the price up a bit, an individual bias adjustment on every tube is a feature I wouldn't be without. Makes life so much easier.

What ever You decide, make sure to post a build thread about it .

Regards
Sam

[sonic assassin]

id go with a small one. i like grit. i also like being able to hear. as a studio guy, i dream of guys showing up with sub 30 watt amps.

[billfitzmaurice]

Originally Posted by 72LML

The question I have how much power should I go for? He basically offered me this:

125 - 175 watts for $300 - $350 in parts
or
225 - 300 watts for $400 - $450 in parts

The difference between 175w and 300w is for all practical purposes inaudible. $100 over the life of an amp is a pittance. The weight of the two options would be the defining factor for me.

[72LML]

edbass, I'll see him tonight at practice see if he can give up some of his sources.

Deluge Of Sound, the only distortion pedal I have right now is a MXR Bass Di +. I don't mind the pedal but all I'm really using if for right now is the Di capabilities. So down the road I'm probably not going to use much for distortion pedals. Between my Musicman and "digging" in a bit maybe I can get the amount of dirt that I like but still have the clean tone when I want.

T-Bird, I'll ask him about putting the individual bias adjustments on the tubes. Thanks for the suggestion and the info.

Volume wise I know there's not a huge difference between 175 vs 300 watts. I'm making the assumption that it will give me a bit more headroom if I want.

If he's cool with it I'll definitely post a build thread. So far I've go the chassis drawn up in CAD and just need to detail it out to let the shop guys get to work on it. (There are some advantages to work for a machine shop I guess )

[mcrracer]

Originally Posted by edbass

Good question. The transformers alone could easily be almost twice that much.
72LML, ask your guitar player where he's getting the iron. If there is a low cost source out there you should share!

IF you are in the business of building tube amps then you know where to get good transformers at reasonable prices. Plus IF you are in the business you are not paying retail prices for your parts. As a business you just can not pay full retail prices and expect to make any money in this game.
If you are just a hobbiest then you may be paying the full retail parts prices.

[edbass]

Originally Posted by mcrracer

IF you are in the business of building tube amps then you know where to get good transformers at reasonable prices. Plus IF you are in the business you are not paying retail prices for your parts. As a business you just can not pay full retail prices and expect to make any money in this game.
If you are just a hobbiest then you may be paying the full retail parts prices.

Wow, thanks for the heads up! You must be referring to that retail/wholesale thing I've heard stories about, I've often wondered about how that worked...
Where do you buy your transformers?

[mcrracer]

I buy my transformers and other parts from sources that only deal on a wholesale level with businesses. Some parts I get straight from the manufacturers because a few other builders and I band together and buy in bulk. There are some parts we buy in 10 thousand piece quantities but we get a huge price break for buying that many. If you need transformers or other parts PM me.

[Rickett Customs]

Yeah, go with the 300w, you'll thanks yourself later on