Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TIMBO on September 21, 2011, 02:19:36 am

Title: TOS REBUILD
Post by: TIMBO on September 21, 2011, 02:19:36 am
Hi guys, Getting things in order for the rebuild.When i built the TOS i got a bit carried away with some add-ons and lost the true effect of the original build. Thankfully Tubenit has come up with some bute ideas and so an upgrade is in order, but there has been so many great changes its hard to know which ones to use. I've started with TOS 8-28-11 and added a reverb and now that the Carolina Hummingbird has arrived on the scene i'm liking the TONE STACK and would like to ask T how they compare and suit each amp as they both have great sound qualities.Thanks
Title: Re: TOS REBUILD
Post by: tubenit on September 21, 2011, 05:09:15 am
I recommend the 8-28-11 TOS tone stack. 

The Carolina HummingBird is a brighter sounding amp for some reason (thru the same speaker & guitar) so I had to take off more of the higher frequencies. And the CHB tone stack is after the cathode follower instead of between the V1a & V1b.

with respect, Tubenit
Title: Re: TOS REBUILD
Post by: stingray_65 on September 21, 2011, 08:38:30 am
I have to ask,

Would the mosfet CF and the CHB tone stack be a good candidate for the TOS?
Title: Re: TOS REBUILD
Post by: TIMBO on September 21, 2011, 02:28:13 pm
Thanks Tubenit, This will be the schem i will go with and the tag strips for the construction. Thanks
Title: Re: TOS REBUILD
Post by: Willabe on September 21, 2011, 04:45:11 pm
Where did you get that tag strip? Man that thing is as long as a river. I don't think I've ever seen one like that before.


         Brad       :icon_biggrin:
Title: Re: TOS REBUILD
Post by: tubenit on September 21, 2011, 05:55:06 pm
Timbo,

That looks good!  Maybe try a 120p to 220p range on the volume pot bright cap & see what works best for you?

Please keep us posted, I am interested in how this build turns out for you.

With respect, Tubenit
Title: Re: TOS REBUILD
Post by: TIMBO on October 04, 2011, 01:58:08 am
Hi guy's,I am wanting to know if any one had any problems with mounting filter caps near circuitry components as i am trying to keep them close to there relative power supply,in other words do filter cap give off any magnetic fields that might upset sensitive components.Thanks
Title: Re: TOS REBUILD
Post by: Geezer on October 04, 2011, 07:51:00 am
I've never had a problem, and in fact, I believe the closer the filter is to the corresponding filtered section, the better.

$0.02    Geezer
Title: Re: TOS REBUILD
Post by: Rev D on October 04, 2011, 12:28:48 pm
 Look at some of Doug's older Plexi designs, there's caps all the way across the board if memory serves? One sec:

(http://www.el34world.com/Hoffman/images/30watt1.jpg)

 There all sit under the board on his early 30 watt heads, must not be an issue?

Regards,

Don
Title: Re: TOS REBUILD
Post by: Tone Junkie on October 04, 2011, 01:56:16 pm
Timbo I like putting mine like this keeps them real close to what Im filtering.
Plus i like how compact and cheap good quality radial caps are.
Bill
Title: Re: TOS REBUILD
Post by: TIMBO on October 04, 2011, 02:14:08 pm
Thanks guys,just another piece of info to add to the list.I'm hoping that i can workout a standard layout that i can apply to other builds and at the same time create a layout that is well grounded and will reduce noise in ANY type of amp.I've tried using the etched boards with turrets but with having some of the connections under the board it makes it difficult to make changes, so this time the tag strips are the go. Any advice,Thanks
Title: Re: TOS REBUILD
Post by: Willabe on October 04, 2011, 03:41:46 pm
Tone Junkie, are the lectro caps in your pic soldered to eyelets under the caps or did you run the leads through hole's in the board and then back (under the board) to the turrets?

Looks real nice.


          Thanks ,    Brad       :icon_biggrin:
         
Title: Re: TOS REBUILD
Post by: stingray_65 on October 04, 2011, 10:28:51 pm
Hi guy's,I am wanting to know if any one had any problems with mounting filter caps near circuitry components as i am trying to keep them close to there relative power supply,in other words do filter cap give off any magnetic fields that might upset sensitive components.Thanks

While E caps do have a wound foil inside them, they do not complete a circuit and are separated by a dielectric and therefore do not act like an inductor.

ANY time an electric current is acted upon there results a magnetic field, usually these fields are so tiny they can be ignored in all but the most crowded and sensitive circuits.



Title: Re: TOS REBUILD
Post by: Tone Junkie on October 05, 2011, 02:26:26 am
I save alot of my snipped off resister and cap leads then will bend one tight around the cap lead and then go to the turrets.
 I usually like the upper quality nichicon caps they seem to have short leads that just poke through the board a little ways, but leaves enough to solder solidly to.
Title: Re: TOS REBUILD
Post by: TIMBO on October 07, 2011, 06:29:22 pm
Hi Guys,Had some time to do some doodling and also had a good read of Merlins Grounding, a lot more made sense this time round, so i tried to do my layout to match as much as his article says. The Layout looks a bit cluttered but i think i've got it pretty well worked out.I did not have any BUZZ problems with the original build but i was hoping that this kind of layout will help with the other problem amps. Thanks
Title: Re: TOS REBUILD
Post by: TIMBO on November 06, 2011, 01:21:36 am
Hi guys, Things are going GREAT. The tag strips are working well and looks like it will all come together nicely. So some pics are in order.
Title: Re: TOS REBUILD
Post by: TIMBO on November 06, 2011, 01:29:41 am
MORE PICS
Title: Re: TOS REBUILD
Post by: birt on November 06, 2011, 03:39:20 am
looks very good. i like those tagstrips too but i cut off some of the feet so i have less ground points and i can use those tags for other connections.
Title: Re: TOS REBUILD
Post by: TIMBO on November 06, 2011, 04:13:13 am
Hi birt, I did cut off some of the feet and tried to use only the ones that did not have a component soldered to it but in the end most of the tags were used so i used a plastic bolt and washer to insulate the foot from the chassis. The three filter caps and there assoc. components are connected to the caps ground and i was going to use the tag foot to ground that cap to the chassis but at the moment i have a wire that i'll will solder to the ground buss as per merlins grounding. Thanks
Title: Re: TOS REBUILD
Post by: tubenit on November 06, 2011, 04:45:20 am
Thanks for sharing the pics!  I am very interested how this turns out for you.

With respect, Tubenit
Title: Re: TOS REBUILD
Post by: Tone Junkie on November 08, 2011, 02:37:05 am
Looks cool I like the way the tags strips look when its all soldered up seems to save space over the turret boards I usually use.
Bill