Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: John on November 05, 2014, 07:22:07 am

Title: Harp amp project, done
Post by: John on November 05, 2014, 07:22:07 am
This is what I've been working on for the last several months. I had started a thread with some questions, but can't find it. Anyway, here's the link to a FB page I set up so that my buddy could see what was happening as it went along.  There's an album "CJSpecial" where the pics are mostly in order. I re-purposed a Webster record player case for the cab. My work is not nearly as tidy as some other's on here (specially Sluckey) but I'm really tickled with the way it turned out, and how it sounds. It's got the digital reverb and switching for harp or guitar. I hate to let it go.  :laugh:




https://www.facebook.com/Loafin.Shed (https://www.facebook.com/Loafin.Shed)




Title: Re: Harp amp project, done
Post by: kagliostro on November 05, 2014, 10:03:53 am

Which are the tube you use on the amp ?

(https://scontent-a-mxp.xx.fbcdn.net/hphotos-xpa1/t31.0-8/10511595_309922645868025_8049039608377037375_o.jpg)

From pinout I suppose V2 = 5879 -- V4 and V5 = 6L6

But which tubes are V1 and V3 ?

---

Is this the old tread ?

http://el34world.com/Forum/index.php?topic=17139.msg171129#msg171129 (http://el34world.com/Forum/index.php?topic=17139.msg171129#msg171129)


Oh, I forgot to say .... nice result   :thumbsup:


K
Title: Re: Harp amp project, done
Post by: SILVERGUN on November 05, 2014, 10:08:46 am
This is what I've been working on for the last several months.
Hey man that's pretty cool stuff right there!
Thanks for the link and glad to hear it turned out to your liking.....
 :thumbsup:
Title: Re: Harp amp project, done
Post by: John on November 05, 2014, 12:12:11 pm
SG, thanks! Like I said, not as pretty as the work I've seen, but at least I'm getting better at the tidiness thing.


K, that's not the schematic. For this amp I used a 6SL7, a 12ax7 for cathode follower into the Brick and as recovery, and then the Russian 5881. When I get home I can post the schematic.


Oh, in the schem you posted, V 1 and V3 are also 6SL7s. I like those tubes a lot. And thanks!
Title: Re: Harp amp project, done
Post by: TIMBO on November 05, 2014, 12:55:06 pm
Cool, Neat enough.  :thumbsup:
Title: Re: Harp amp project, done
Post by: DummyLoad on November 05, 2014, 02:34:38 pm
nice!   :icon_biggrin: 


--pete
Title: Re: Harp amp project, done
Post by: HotBluePlates on November 05, 2014, 06:21:30 pm
Nice hammertone paint! I think I smell Rustoleum...  :laugh:

I think I recognize the chassis, too, before the guy who made it had a fire & stopped making them.
Title: Re: Harp amp project, done
Post by: John on November 05, 2014, 07:12:28 pm
Nice hammertone paint! I think I smell Rustoleum...  :laugh:

I think I recognize the chassis, too, before the guy who made it had a fire & stopped making them.


Right on both counts!
Title: Re: Harp amp project, done
Post by: John on November 05, 2014, 07:15:59 pm
Forgot the schematic. Only thing not shown is the power supply for the brick.


Oh, and if I've not drawn the external speaker jack correctly, please let me know. It's wired so that plugging in shorts out the on board speaker, as most do.
I originally had the standard 470r for the power tube, and wanted to try the 300 since I'm using a tube that'll handle 23 watts Pdiss. Sounds better imo, but it sure did drop the rest of the voltages too. I think the PT is a tiny bit undersized.  :icon_biggrin: