or Connect
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › A Very Compact Hybrid Amp
New Posts  All Forums:Forum Nav:

A Very Compact Hybrid Amp - Page 13

post #181 of 2213
What do you use to make those annotations?
post #182 of 2213
Quote:
Originally Posted by digger945 View Post
What do you use to make those annotations?
Adobe Photoshop...
I do have a freeware tool that works halfway decent at work - Can let you know its name on Monday if you fire me a PM.
post #183 of 2213
Gotcha. Thanks.
Do you know the circle diameter of the tube socket?
post #184 of 2213
Quote:
Originally Posted by runeight View Post
Boards have shipped to those interested.
Great news, Thank you very much.
post #185 of 2213
Quote:
Originally Posted by digger945 View Post
Do you know the circle diameter of the tube socket?
Putting together a Trivial Pursuit - Tube Amp Edition? Hey now, that would be fun @ a meet..

My tube socket measures 22mm dia. BTW builders will be getting a case hole guidance PDF I think...
post #186 of 2213
Thanks for the replys, have a few more questions.


Quote:
New BoM changes maybe 6-8 resistors & uses smaller diameter C5P & C10P caps.
Does this relate to changes for the next lot of boards only, or do we need to use 12.5mm caps on the proto boards(There is room for 16mm according to pdf)?


The heater switch on the BoM is listed by Mouser as Momentary, should it be locking?


cfcubed, Have just read your post on fuses, great info. Does this part
Quote:
This only when you short something by mistake OR bad build error like wrong orientation on PS diodes.
mean the fuses is only need during the build?

Since there is no need for any adjustments to be made when Tube rolling could an external/in-line fuse be used while building and then ditched once build completed?
Would mean one less thing to squeeze in....
post #187 of 2213
Quote:
Originally Posted by Forte View Post
Does this relate to changes for the next lot of boards only, or do we need to use 12.5mm caps on the proto boards(There is room for 16mm according to pdf)?
Your "o" version (or newer) of BoM contains the 12.5mm parts... There IS room for 16mm C5P & C10P, as in my pic, but they had to tilt inward a little
Quote:
Originally Posted by Forte View Post
The heater switch on the BoM is listed by Mouser as Momentary, should it be locking?
Ah, that would bad... My mistake. It sure must be locking. Essentially any smal SPST, SPDT, DPDT slide or other switch would work. It only either makes or breaks two wires coming off board. Sorry...
Reason for submini heater slide mounted horizontally & w/small actuator is so that it is not confused with a power switch!
Quote:
Originally Posted by Forte View Post
cfcubed, Have just read your post on fuses, great info. Does this part mean the fuses is only need during the build?
I guess that gets you the safety when you need it most... During the build & after its confirmed. Up to you though, if a short occurred somehow those A/C adapters are a bear to pry apart.
Although, as I recall, the 2 or 3 times I blew fuses were from the A/C adapter plug shorting against something on my bench

BOM UPDATE: Heater slide should NOT be MOMENTARY, let's go with Mouser 10SM002 or RadioShack 275-406 instead.
post #188 of 2213
Quote:
Originally Posted by cfcubed View Post
Y

BOM UPDATE: Heater slide should NOT be MOMENTARY, let's go with Mouser 10SM002 or RadioShack 275-406 instead.
Too late for me! But I have some small paddle switches left over from my SOHAII build - how much current moves through the switch (It's mounted off board, correct?)

BTW - Due to a happy accident, I have my board. Nice work tight clearances. No cocktails and soldering with this build!
post #189 of 2213
Quote:
Originally Posted by wiatrob View Post
Too late for me! But I have some small paddle switches left over from my SOHAII build - how much current moves through the switch (It's mounted off board, correct?)
Sorry, no electronics store around? It is off-board & carries virtually no current (1/8th watt?)... Anything that you can't easily switch from 6.3V -> 12.6V by mistake will do... Something that indicates its position is best (like the slide).
Actually I have an extra RS submini slide I could 1st class mail to you if you can't find one (just let me know through my real emai that you now havel

Great you have the board!
post #190 of 2213
Quote:
Originally Posted by cfcubed View Post
Great you have the board!
Parts will all be here Monday - I will have this done for the meet (fingers crossed).

I have access to good electronics stores (JB Saunders in Boulder) and my parts box is getting big. I was just lamenting that I didn't pay attention.
post #191 of 2213
The part number recommended for "R16L, R16R, R17L, R17R, R5S, R6S, R7S, R8S" is Carbon Film not the recommended Metal Film?

A Vishay Dale is available in 6.81 ohm but is pricey.

Would a RN55D6R98FRE5 be ok at 6.98 ohm?
post #192 of 2213
Quote:
Originally Posted by Forte View Post
The part number recommended for "R16L, R16R, R17L, R17R, R5S, R6S, R7S, R8S" is Carbon Film not the recommended Metal Film?
A Vishay Dale is available in 6.81 ohm but is pricey.
Would a RN55D6R98FRE5 be ok at 6.98 ohm?
Hey you're doing a great job going over the BoM! We'll have to somehow incorp your source/part discoveries for others...

Re: 6.8s - Forsakenrider & I are using earlier BoM Mouser 299-6.8-RC in our builds.. Think runeight is tweaking comps a bit but don't know how critical the changes are. For example, earlier 2.2ma 1N5306s were on the BoM as alts to save $5 or so but probably best to stick w/speced 2.0ma 1N5305s for consistency in builds.

WRT heater chokes - I posted the pic a bit back so you could see the clearances... E.G. we have 14mm X 7mm max space for L2H 220uH toroid, but really any 220uH -> 330uH toroid w/min 800ma that fits is fine.

Edit: Although its important for 1st ten prototypers to try to stick to BoM parts this does not preclude some variation later. E.G. Forsakenrider & I have a pent up coupling cap demand so we're going in on a soniccraft order. Within only one cap in primary signal path in this amp (C4L & C4R) & about 14mm x 20mm space above board for each of them, we may be trying Gen II 0.22µF 0.27" x 0.73" caps there.
Also with your help we are down to only 2 non-Mouser parts & that screams for GroupBuy / Bundling down the road.
post #193 of 2213
Quote:
Originally Posted by cfcubed View Post
Hey you're doing a great job going over the BoM!
Have to! Shipping to Australia is either slow or expensive(Mousers minimum shipping for me is $48 AU) so you don't want to get it wrong or leave anything out since there is a very limited choice locally.


Quote:
With only one cap in primary signal path in this amp (C4L & C4R)
Timely post, I had been wondering about the Amp section caps today, look forward to seeing if the Sonicaps make a big difference.
Would upgrading the Electrolytics in the Amp section have any impact if they are not in the direct signal path?
Mouser list a Muse ES Bi-polar at 10u 35v although not available until April and not available any where else I can find. Still not found anything for C1L/R though.
post #194 of 2213
Thread Starter 
Quote:
Originally Posted by Forte View Post
The part number recommended for "R16L, R16R, R17L, R17R, R5S, R6S, R7S, R8S" is Carbon Film not the recommended Metal Film?

A Vishay Dale is available in 6.81 ohm but is pricey.

Would a RN55D6R98FRE5 be ok at 6.98 ohm?
Yes, these are a good sub for the Xicon resistor in the BoM. Nice work.
Dr. Cavalli gained notoriety with his first DIY amplifier projects. His success has blossomed into Cavalli Audio, a world leader in amplifier design.
Reply
post #195 of 2213
Quote:
Originally Posted by Forte View Post
< snip >
Timely post, I had been wondering about the Amp section caps today, look forward to seeing if the Sonicaps make a big difference.
Would upgrading the Electrolytics in the Amp section have any impact if they are not in the direct signal path? < snip >
Cap upgrades & effects have a life all their own on these boards (as do wire types & even # of strands & insulation... I found this thread interesting WRT coupling caps but you are unlikely to find me spending > $10 USD a on cap A tube maybe but not a cap. Although Forsakenrider & I may post back WRT C4 bit, personally don't see much else going on (or needing to go on) in this area.

IMHO I'd shy away from cap "upgrades" other than maybe those C4 couplers myself. And I don't expect night & day improvement w/Sonicaps there. The amp sounds so good to the two prototypers so far thinking the most noticeable effect will come from tube choice. Of which there is a heck of a lot.
As before, my fav SOHA Raytheon CK5814A & GE 5963 are unlikely to be favs in this amp as its running tubes much closer to where they are designed to run (80V / 2ma plate). Coupled with flex heater, tubes like Teles, Mullards, Amperex BBs dismissed in amps running tubes at lower voltages & current enter the fray, while more economical/readily available choices may shine too (like my EH).
New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › A Very Compact Hybrid Amp