Valve amp head to cab question

Discussion in 'Ampage Area' started by Jockabilly, Apr 4, 2019.

  1. Jockabilly

    Jockabilly Synchromatic

    Age:
    47
    593
    Sep 15, 2018
    Argyll
    Hi all, despite being a guitar player of some thirty plus years standing I must confess to ignorance when it comes to knowing how well different powered valve amps will work with particular speakers so I am interested in a little expert help.

    I currently have a 50 watt Bassman clone head which is paired with a 4x10 celestion loaded cab meant for this particular amp and coming in at eight ohms impedance. For domestic use I can't really turn this amp up to get the best of the tube sound. From the same manufacturer I can pick up a 5 watt valve amp which says "rated power output:2 Watts" on the back of the amp that has outputs for 1x 8 Ohms, 1x 4 Ohms and 2x 8 Ohms. The question is - Will this amp drive my 4x10" cab or will it not have enough power?

    I have contacted the company but they couldn't actually tell me whether what I propose would work so I need someone with expertise in this field.

    This 5 watt amp is sold by the company with a pair of 10" cabs as a package but can be bought on it's own for a very reasonable price.
     
  2. wabash slim

    wabash slim Friend of Fred

    Age:
    69
    Feb 10, 2010
    lafayette in
    If it says 2 watts, then it certainly can't be 5, aside from peak power. The only rating for wattage that matters is RMS. It probably won't drive the 4X10" cab, tho you could try it. It'd be very underpowered. That cab can easily handle your 50 watt Bassman clone (Bassman was originally designed for a 4X10 cab). That cab can be wired in series/parallel to get 8 Ohms, or in parallel for a 2 Ohm load. Were it me, I'd find a single 8" or 10" speaker for the small amp for home use.
     
    benjwri and Waxhead like this.
  3. swivel

    swivel Synchromatic

    635
    May 13, 2018
    PNW
    A couple t hings.
    The Bassman came at 4 ohms output. I assume your clone was built to be 8 ohms.
    I doubt the 2/5 watt will drive the 4 x 10 well but it will likely work and make sound. It might even be fine. I have hooked many cabs, large and small, to many amps, large and small. They universally almost always work pretty well... but I dont go try to play a gig with many of the experiments! I seriously doubt a 5 watt amp will be gigable.
    Some heavy duty speakers specify a minimum wattage, mostly so they will sound good I imagine. JBL was one of them.
     
    Last edited: Apr 5, 2019
  4. Jockabilly

    Jockabilly Synchromatic

    Age:
    47
    593
    Sep 15, 2018
    Argyll
    The cab is loaded with 4 Celestion 10-30 speakers and is 8 ohms rated for 120 Watts RMS and yes my clone was built to work at 8 ohms. As far as I can see from the cursory look over I gave the amp the basic circuit layouts are near as darn it identical, to the '63 bassman with the solid state rectifier although some of the component values are slightly different.

    The reason I am interested in a low power head is so that I can drive it hard at home. The 50 watt head is just way, way too much amp to turn up above 1 or 2 at home without deafening myself and anyone within a mile or so. The problem is that I have very limited space so another amp. whether combo or stack is out of the question and I thought it would be nifty to get a much lower power head that could plug into the same cab and sit on top of the 50watt head and using the same cab therefore not taking up any more floor space.

    Problem is that, being very rural and not being able to travel any great distance (I look after my wife who is in poor health) I'm having to examine options 'blind'.
     
    new6659 likes this.
  5. Sid Nitzerglobin

    Sid Nitzerglobin Country Gent

    Jun 8, 2015
    fROMOHIO
    I like my low watt amps just fine driving a couple 12"s and a couple of 10"s that would wind up over 100W of speaker in total, gives me more feeling of weight/size through them than a single 10" and doesn't seem to lose anything in the process.

    You could try some lower wattage speakers in the 4x10 to split the difference if you felt it wasn't to your liking w/ the stock ones.

    Just my .02 though.
     
    Jockabilly likes this.
  6. somebodyelseuk

    somebodyelseuk Country Gent

    Jan 22, 2013
    Birmingham, UK
    The output impedence isf any amp is dependant on it's output transformer, so just because the original blah, blah, blah was 4 ohms, does not mean the clone MUST be. If it says 8 on the back, assuming the builder knows what he's doing, it's 8.
    Okay, as 'Wabash' pointed out, YOUR cab is likely made up of four 8 ohm speakers, connected in series/parallel fashion, and likely to be around 25 watts each.
    IF you're handy with a soldering iron, you understand simple electronic circuits, or you know someone who does, you CAN use what you've got.
    Get the cab wired so that it can use the current configuration for the big amp and uses one speaker for the small one, whether on a switch or sepatate jack socket, and you're golden.
    It's doable, and costs peanuts.

    For the doubters, the Vox aC4TV 10 came with a 30 W speaker, so it the amp you're considering should be capable.

    My advice, get a screwdriver out and take a look at the labels on the speakers, check their specs and take it from there. Trying the amp with the current config. will do no harm. As long as the impedance is correct. Worst case is you don't like how it sounds.
     
    Last edited: Apr 5, 2019
    wabash slim, Jockabilly and wildeman like this.
  7. Ricochet

    Ricochet Gretschified

    Nov 13, 2009
    Monkey Island
    The real point here is 5W(or even 1W) will still be offensively loud through a 4x10"...
     
  8. Dave-B

    Dave-B Synchromatic

    961
    May 23, 2016
    Scotland
  9. wildeman

    wildeman Gretschified

    May 10, 2015
    norcal
    This!!
     
  10. Jockabilly

    Jockabilly Synchromatic

    Age:
    47
    593
    Sep 15, 2018
    Argyll
    @Dave-B I have considered the attenuator option but I have often heard people say that the sound quality isn't nearly as good when using them and the 5W amp I am talking about, Subzero H5, which is also from Gear4music would only cost me a little over £1 more than that attenuator.

    The Bassman clone I refer to is actually the Gear4music Subzero H-50r which I have had for almost a year now and is every bit as good as my '63 Bassman at a mere fraction of the cost.

    To my shame I have to admit here that I was trained as a military Radar and Radio tech and worked with both tube and solid state tech but I never got involved with audio electronics and I have forgotten more than I ever knew about the trade and haven't done much more than change a pot or pickup now and then for over twenty years now.
     
  11. BuddieGreen

    BuddieGreen Gretschie

    287
    Sep 3, 2018
    indiana usa
    i have a small 2w fender head 8ohm. plugged into a 4x12 16ohm cab and have no problems, sounds great and very loud for such a small amp. not a gigging setup but blasts the family room
     
    Jockabilly likes this.
  12. swivel

    swivel Synchromatic

    635
    May 13, 2018
    PNW
    The 10-30 speakers are pretty light duty IIRC so it may work fine. Will it still be too loud at home. Quite possibly and more so with the 4 x 10 speakers
     
    Jockabilly likes this.
  13. markeebee

    markeebee Country Gent

    It'll work fine. No problem.

    You won't get the same feeling of "ooomph" of course, simply because you'll be moving less air. Also, you won't get the speaker breakup which might be a component part of the sound you like.

    Having said that, the 5W amp will obviously have different valves, different circuit topology, different transformers, different filtering etc etc to its big brother, so it's gonna sound a bit different anyway.

    But, definitely, no problem in compatibility between your cab and the little amp. Have at it.
     
  14. hcsterg

    hcsterg Country Gent

    Feb 13, 2012
    France
    For sure !

    I use 8" and 10" speakers in my 5-watters amps, and it's already very loud for home use...

    The Orient-Express has a 8" Utah 50's reconed AlNiCo and the Val-King has a Vintage47 8" AlNiCo hemp cone speaker :
    [​IMG]
    [​IMG]

    The Comet has a 10" Utah 50's reconed AlNiCo speaker :
    [​IMG]
    [​IMG]

    I think that you may not experience a big difference between a 50W and a 5W in a such 4x10" cab - for cool home use, I mean. In both case, you will be loud !

    But it's me, OK ? :D

    A+!
     
  15. Jockabilly

    Jockabilly Synchromatic

    Age:
    47
    593
    Sep 15, 2018
    Argyll
    Thanks for the replies, I think I will take a pop at one. I am not sure what amp the 5w head is based on. It has an ECC83/12AX7 and an EL84 according to the website so maybe more of a British flavour?

    I can be fairly loud at home but the 50W head means having to ever so gently turn the volume up from zero to somewhere around 1-2 so very difficult to adjust from earsplitting to just loud and there is no way to be much less than loud.

    @hcsterg Your 'The Comet' amp is a thing of beauty in the 'looks' department! You would swear it was straight out of an episode of Hercule Poirot or belonged to Django for when he wanted to really rock. What sort of money does an amp like that cost?
     
  16. markeebee

    markeebee Country Gent

    Holy crap, 100 quid for an all valve head? That's bonkers! They look really cute too, nice vinyl & Grillcloth combination.

    Background hum is sometimes an issue with these, apparently. The same amps are branded 'Belcat' elsewhere, Subzero is unique to Gear4music.
     
    Jockabilly likes this.
  17. Jockabilly

    Jockabilly Synchromatic

    Age:
    47
    593
    Sep 15, 2018
    Argyll
    I have seen a few comments about hum but I have to say that the 50 watt head hums very slightly on standby but once it's turned on you can't hear a thing. I was very impressed with it although I wondered how long it would last but, to date it hasn't missed a beat and sounds incredible. I think that the Belcat name was originally owned by Gear4Music as well.

    I believe these, like many other amps all originate from the Shenzhen Grand Technology Ltd company in China who will make you just about any kind of amp you fancy.
     
  18. Jockabilly

    Jockabilly Synchromatic

    Age:
    47
    593
    Sep 15, 2018
    Argyll
    Doing a little research I am guessing that the 5W head is essentially a Fender champ circuit. I have read online that their 20Watt combo circuit is pretty much identical to a Fender Blues Junior.

    Shenzhen Grand do just about every 'style' of amp going it seems.
     
  19. loudnlousy

    loudnlousy Friend of Fred

    Age:
    53
    Oct 18, 2015
    Hildesheim, Germany
    Part of the sound of a Bassman are the 4x10 speakers pushed really hard.
    Speakers tend to break up when pushed ( an EVM 12 will stay quite neutral even on high volumes, though).
    Of course you will never get this (wanted) effect when plugging a 4 watt-amp into a 4x10 that is expected to be fed wit 35 watts+.
     
    Jockabilly likes this.
  20. stiv

    stiv Synchromatic

    771
    Sep 12, 2014
    Florence, Italy
    Watch out with that 5w champ mate.
    I plugged mine in my 8ohms/300w 15” Eminence Delta equipped cab and I fried the power valve.
    I have no idea about the reason it happened, but it happened.
     
    Jockabilly likes this.
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