Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: mresistor on September 30, 2017, 06:18:43 pm

Title: Baldwin to 5F6A done
Post by: mresistor on September 30, 2017, 06:18:43 pm
I finally did finish the conversion of a Baldwin Orgasonic to a Hoffman 5F6A and wanted to show you all.  Also wanted to thank all that assisted. It was really a difficult project but can be done. There is little space inside the chassis horizontally, but being 3" deep there is vertical space. The cabinet is made from recycled wood and I have no idea where I acquired the brown Naugahyde in the past but finally used it up. The cab has two spring loaded handles on the ends. It does sound somewhat like a bassman and has a little of the grind and some pretty nice cleans. The glue seemed to shrink the haugahyde some when drying so it opened up the corner seams a little.
A sincere thank you to everyone that helped.
Title: Re: Baldwin to 5F6A done
Post by: tubenit on September 30, 2017, 08:30:31 pm
Wow!  That turned out really nice!  THANKS for sharing the photos and info.

With respect, Tubenit
Title: Re: Baldwin to 5F6A done
Post by: DummyLoad on September 30, 2017, 10:57:00 pm
nice work!   :icon_biggrin:


--pete
Title: Re: Baldwin to 5F6A done
Post by: TIMBO on September 30, 2017, 11:57:53 pm
Great work :thumbsup:

Mitred corners are a bugger, with black tolex I fill the gap with supa glue and colour with a black permanent marker pen.
you might be able to do similar with a brown marker. :dontknow:
Title: Re: Baldwin to 5F6A done
Post by: tubeswell on September 30, 2017, 11:59:25 pm
Nice indeed!
Title: Re: Baldwin to 5F6A done
Post by: sluckey on October 01, 2017, 06:41:36 am
Very well done!
Title: Re: Baldwin to 5F6A done
Post by: mresistor on October 01, 2017, 10:41:58 am
Thanks guys  :icon_biggrin: . Timbo thanks for the suggestion.
Title: Re: Baldwin to 5F6A done
Post by: SILVERGUN on October 01, 2017, 12:30:07 pm
All of these sweet build threads are starting to add up.
I feel a parts order coming on.
Looks great and thanks for the inspiration!
Title: Re: Baldwin to 5F6A done
Post by: bnwitt on October 01, 2017, 06:47:13 pm
Another beauty.
Title: Re: Baldwin to 5F6A done
Post by: CraigB on October 01, 2017, 07:16:44 pm
That's a beautiful thing!  Very nice clean wiring and the cab looks sweet.  Well done, Sir!
Title: Re: Baldwin to 5F6A done
Post by: mresistor on October 07, 2017, 06:41:07 pm
Well I was playing around with bias on a set of 5881 that are not very matched, and inadvertently made contact with pins 3 and 2 on one of the sockets, like who hasn't done that? I must have bumped one of the leads. So I had to replace the 100 ohm resistors of course and while in there took some better pics so anyone interested can see the components.

Title: Re: Baldwin to 5F6A done
Post by: mresistor on October 07, 2017, 07:27:51 pm
I took those 5881's out and installed a more matched set of EL34's and I have to say, so far I really like them in this amp.
Title: Re: Baldwin to 5F6A done
Post by: Willabe on October 07, 2017, 08:08:37 pm
Very nice looking work.   :icon_biggrin:

I do have a question, why did you put the turrets so close together for the yellow coupling caps? The leads are very short, I'd be worried about over heating caps soldering them in.
 
Title: Re: Baldwin to 5F6A done
Post by: mresistor on October 09, 2017, 04:23:51 pm
Hi Willabe - the turrets are spaced exactly like the Hoffman layout. I didn't alter it at all on this one. Oh  ok  sorry   I didn't keep the heat on the wire and turret any longer than necessary to flow the solder.  I haven't had any problems in the past but in the past, and especially since I had vertical room in the chassis, I have and could have left the leads longer and then bent them underneath the caps to fit the turrets.
Good call Willabe. I will do that next time.

Title: Re: Baldwin to 5F6A done
Post by: Willabe on October 09, 2017, 09:57:05 pm
- the turrets are spaced exactly like the Hoffman layout. I didn't alter it at all on this one.

Doug probably spaced those turrets for Xicon caps, they are shorter in length than the yellow caps you used. (Mallory's or Mojo's?)   
Title: Re: Baldwin to 5F6A done
Post by: mresistor on October 10, 2017, 08:17:23 am
The yellow caps are ETR MET out of Taiwan I think..   http://www.etr.com.tw/eng/dc_use_film_capacitors/m_polyester/dc01_07.htm (http://www.etr.com.tw/eng/dc_use_film_capacitors/m_polyester/dc01_07.htm)  ETR is an OEM supplier with major customers that include : CDE (Cornell-Dubilier), Sony, National, Canon, APC, LG, LEO, Bosch, B&D, Askey and HP.