Contessa ca 15 mini bass

Discussion in 'Amps [BG]' started by cryan, Feb 24, 2008.


  1. cryan

    cryan

    Joined:
    Feb 24, 2008
    15 inch speaker two 6v6 two 7025 says it is made by Hohner but can't find any info. Just bought this amp in Tucson at a thrift store and it seems to be working OK. Thanks Cliff
  2. Catanova

    Catanova

    Joined:
    Apr 7, 2011
    Location:
    Golden CO
    I know I am responding to an very old post, so maybe this is a waste of time...but now its 2012, maybe someone has some insight on these now.

    I have the same amp and it has been my main bass practice amp for 5 years or so. I love the tube tone especially when cranked and it IS loud. I have used it live a few times but its only useful for a small setting, unless you mic it.

    These were built by Bartell of California. Useful web refs are few about this amp, but you can learn a bit about the builder. I do know that they were branded for Hohner and Natural as well. Mine has no brand mark. There were virtually identical guitar versions made as well. I spotted one in Longmont earlier this year, but did not have the foresight to buy it, as mine was working ok.

    I have used this amp in my experiments of learning how to repair tube amp circuits, as it needed some work shortly after I got it and now have done various small repairs on it. But last month the 6ca4 rectifier tube died, and all my troubleshooting afterwards was unsuccessful. I took it in for professional repair today and will post a followup if I can justify the repair cost. IMO these amps were probably unappreciated in their day, given the competition they were up against. Dont know how many were built, but I would guess a lot of them are in the graveyard now...
  3. The EH Man

    The EH Man Proud Registered Supporter of Talkbass Supporting Member

    Joined:
    Dec 24, 2008
    Disclosures:
    owner: RonSound effects and repairs
    Some of those amps were made by Hohner, post-Bartell. All the Bartell-made units I've seen had 12" speakers.
  4. Catanova

    Catanova

    Joined:
    Apr 7, 2011
    Location:
    Golden CO
    Well, my Contessa is finally working again. :hyper: Turns out that one of the 6v6 tubes had a shorted cathode. Because of the circuit design, a shorted power tube will cause the one side of the rectifier (6ca4) to short out due to the current draw. Was pretty sure there was a bad transformer and I thought I had tested ALL the tubes properly during my own diagnosis, but I didn't catch the bad 6v6. :oops: Thankfully the problem didn't ruin anything else in the amp. But since I did a full cap job on it prior to taking it in to a pro, this amp now SHOULD be reliable for the long term, and it sounds great once again!
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  6. bedrockhead

    bedrockhead

    Joined:
    Jan 15, 2010
    Location:
    Arkansas
    My band's guitarist picked one up for 95 bucks the other day. Not a whole lot of info on these amps. Cranked all the way up it has early '70s Keef tone all over it, and that's what he wants. "Mini-Bass" but kills as a guitar amp. Not crazy loud, but mic'd up it's just fine. Had to be mic'd, otherwise my Peavey Mark IV 400 Series bass head on 3 and 1x15/1x18 was killing him. Looks all original, including the tubes (CTS speaker dated 38th week of 1969). He wants to retube it, but as good as it sounds now, I dunno.
  7. will33

    will33

    Joined:
    May 22, 2006
    Location:
    austin,tx
    Disclosures:
    Use of this field for any other purpose is prohibited
    Don't fix what ain't broke...though if it is all original it could use a cap job for reliabilities sake.
  8. Catanova

    Catanova

    Joined:
    Apr 7, 2011
    Location:
    Golden CO
    These have a nice breakup, fer sure, that of a 6v6 getting pushed. Apparently the circuit was based on a 60's Fender Pro. I picked mine up for $120, which seemed a lot at the time. Great for guitar. Changed and compared several sets of old tubes in it (amperex, rca, telefunken, ge) and switching tubes in this amp is no huge deal tonewise. Currently using amperex 12ax7 bugle boys and they sound great. Have plugged a 12" cab into the "extension out" jack for a bit more volume occasionally, but don't trust the amp is capable of long sessions at Max power. Usually use it for practice and sometimes as a monitor at gigs.

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