Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Cabinets-Speakers => Topic started by: Alleycat on April 17, 2018, 07:12:52 pm

Title: Attenuator with Holland Gibb Droll
Post by: Alleycat on April 17, 2018, 07:12:52 pm
New here so sorry if this is not the place but figured someone may know. I have a Holland Gibb Droll 4x10 (50W) that has a separate speaker/tube for reverb. It is a hot rodded B59 Bassman circuit from what I understand. Out of the amp are (3) 8 ohm speakers wired in Parallel via 1/4" jack. If my math is right this would be 2.67ohm? There is a RCA jack also coming out of the amp and through reverb unit that goes to a dedicated speaker. I am not a huge fan of the reverb unit so losing it and having a 3x10 cab wouldnt make much of a difference to me and usually run it this way with a delay pedal anyways. Amp sounds INCREDIBLE at 5+ with channels jumped but is VERY LOUD. Would like to add attenuator such as a hot plate but have been leery. I would think that a 2 ohm attenuator with it left as is would not cut the dedicated reverb speaker? Not an amp guy and would love some thoughts before i purchase a 2.67 ohm hot plate and be thinking wrong. Thanks for any help!
Title: Re: Attenuator with Holland Gibb Droll
Post by: sluckey on April 17, 2018, 07:33:24 pm
Show us a schematic
Title: Re: Attenuator with Holland Gibb Droll
Post by: Alleycat on April 17, 2018, 07:40:03 pm
I have searched everywhere for one. Oddball amp. Everything I have read says it is a 59 Bassman circuit but I have not found a Bassman with dedicated reverb speaker. Pretty sure this was a Holland thing. Company is no longer around and very little info out there on them except they sound good.
Title: Re: Attenuator with Holland Gibb Droll
Post by: Alleycat on April 17, 2018, 08:01:51 pm
Basically looks like this in cab. Not sure whats happening inside...
Title: Re: Attenuator with Holland Gibb Droll
Post by: Alleycat on April 17, 2018, 08:18:41 pm
Looks like the only place I can put an attenuator is at the 1/4" jack to the (3) 8 ohm speakers. In doing so seems like it would only attenuate the load to those 3 speakers and the reverb speaker would be playing on whatever the amp is set at (un-attenuated) If I disconnect the reverb RCA jack at the amp and just use the attenuator at that location this should be 2.67 ohms?
Title: Re: Attenuator with Holland Gibb Droll
Post by: Alleycat on April 18, 2018, 02:04:34 pm
Got my answer direct from Mike Holland today. Very helpful and full of info. He said the way the circuit is designed a 2.67 hot plate works great with or without the reverb circuit plugged in.