[cobaltmute]

Quote:

So, on the transformer ... bigger is not better.
 
A single 30-0-30/400mA transformer will do for two channels. Anything with higher spec than this runs various risks for power dissipation in the rail regulators and/or too much voltage into the regulator.
 
My strong suggestion is to find one with this or close to this spec.

 
I'm not worried about voltage input into the regulators, more about dissipation.  For the cost, I can always buy one, and test since I'm going to order other stuff as well.

 

[FallenAngel]

Not to take this off track, and I'll gladly do this over PM or another thread, but how about a small group-buy for Antek transformers (especially nice for Canadians to save lots on shipping).

 

[BoilermakerFan]

 
Quote:

way too spendy if you ask me..rather go for off the shelf Toroids and a secondary heater transformer. Add a heater delay and you are all set.

 
I prefer cleaner, hum-free iron. 

 
I asked Richard for a quote on the following spec:
 
120/240 primary, (2) 60VCT @ 200mA, and (2) 7V @ 500mA in both banded open as well as shielded and fully encapsulated.  The dual voltage primary adds $5 or $10 to the cost, but IMO is worth the little extra up front to allow sale of the unit to most of the world later. 
 
Electra-Print units under 200VA have generally been within $10-$15 of the SumR shielded and encapsulated iron.  The E-I PS iron would yield cleaner power coming in, but it's a larger package to fit in a chassis. 
 
EDIT:  Broskie has a nice little two position AC power switch kit for $6.  Off-winding 1 power on-winding 1 and winding 2 power on.  So it's a simple, low cost way to power up the heaters, then power up the amp.  No TDRs, no more complex than it needs to be, but it's just a simple rotary switch so no cool illuminated momentary power push buttons either...

 

[cobaltmute]

Quote:

Not to take this off track, and I'll gladly do this over PM or another thread, but how about a small group-buy for Antek transformers (especially nice for Canadians to save lots on shipping).

I'm ordering three or four from Antek so I'm in.

 

[fishski13]

Quote:

 
 
I prefer cleaner, hum-free iron. 

 
I asked Richard for a quote on the following spec:
 
120/240 primary, (2) 60VCT @ 200mA, and (2) 7V @ 500mA in both banded open as well as shielded and fully encapsulated.  The dual voltage primary adds $5 or $10 to the cost, but IMO is worth the little extra up front to allow sale of the unit to most of the world later. 
 
Electra-Print units under 200VA have generally been within $10-$15 of the SumR shielded and encapsulated iron.  The E-I PS iron would yield cleaner power coming in, but it's a larger package to fit in a chassis. 
 
EDIT:  Broskie has a nice little two position AC power switch kit for $6.  Off-winding 1 power on-winding 1 and winding 2 power on.  So it's a simple, low cost way to power up the heaters, then power up the amp.  No TDRs, no more complex than it needs to be, but it's just a simple rotary switch so no cool illuminated momentary power push buttons either...

for those looking for an EI in the PS, Partsconnexion has the Hammond 167G60 60V C.T./.5A: http://www.partsconnexion.com/hammond_fil_encl.htm
 
for heater EI, no reasonably sized "matching" TX from the 167-series.  the 266-series is a little "nicer" to look at compared to the 166-series and a little more flexible with dual primaries and secondaries.  this one would work, but the lead-time is 4wks: http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.z_homepage_link=hp_go_button&KeyWords=266G14&x=0&y=0
 
otherwise, the "economical" 166J8 (8.5V C.T./1A) or 166L8 (8.5V C.T./2A) should work with with UF4002 rectifiers in the heater supply?  http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/UF4002/?qs=sGAEpiMZZMtEwUVCuofpuGhtK2I2zIFHcv3dRFvTnkM%3d.  add a single 166G60 (60V C.T./0.5A) in the PS.  Partsconnexion has a good selection of 166-series:  http://www.partsconnexion.com/hammond_fil_open.html.  only $43 for both the heater and PS TX.

 

[jdkJake]

 
 
I prefer cleaner, hum-free iron. 

 
I asked Richard for a quote on the following spec:
 
120/240 primary, (2) 60VCT @ 200mA, and (2) 7V @ 500mA in both banded open as well as shielded and fully encapsulated.  The dual voltage primary adds $5 or $10 to the cost, but IMO is worth the little extra up front to allow sale of the unit to most of the world later. 
 
Electra-Print units under 200VA have generally been within $10-$15 of the SumR shielded and encapsulated iron.  The E-I PS iron would yield cleaner power coming in, but it's a larger package to fit in a chassis. 
 
EDIT:  Broskie has a nice little two position AC power switch kit for $6.  Off-winding 1 power on-winding 1 and winding 2 power on.  So it's a simple, low cost way to power up the heaters, then power up the amp.  No TDRs, no more complex than it needs to be, but it's just a simple rotary switch so no cool illuminated momentary power push buttons either...

The shielded and encapsulated version still sound interesting. Especially since I ultimately want to do a single enclosure with this amp.

What kind of lead time do those usually have?

Still looking for options, keep them coming.

 

[ujamerstand]

Quote:

I'm ordering three or four from Antek so I'm in.

Count me in for the antek as well.

 

[cobaltmute]

Quote:

Regarding the BJT version. jdkjake and I will provide the alternate parts for this version and the design center transistors will be MJE243/253. Anything that biases close to these should work.

 
Quote:

Just a quick note, the MJE243 seems to be backordered at both Mouser and Digikey.
 
So, I would look to source those elsewhere as the Mouser expected delivery date is in November!?!

I have 2 each of the MJE243/253 so I have no need of them.
 
Is there a reason you guys want to supply to parts - I have no issue with ordering for myself.
 
I know I said I was going to build with 2SC2238/2SA968, but I think I'm going to change that.  When I was looking on my bench to check for the MJEs, I realized I have some other transistors that may be a good fit - 2SB1186A and 2SD1763A.  Extras from a Kumisa build.

 

[runeight]

No intention to supply parts. I just meant that we'll provide part changes in the BoM for the BJT version.

 

[cobaltmute]

Ahh.  Misunderstood what you said.

 

[BoilermakerFan]

 
Quote:

The shielded and encapsulated version still sound interesting. Especially since I ultimately want to do a single enclosure with this amp.

What kind of lead time do those usually have?

Still looking for options, keep them coming.

Lead times from SumR are generally about one week with encapsulated units.  Less with the open, banded units by two days or so.
 
Here is the pricing for 120/240 primary, (2) 60VCT @ 200mA, and (2) 7V @ 500mA:
 
[size=x-small]- fully encapsulated and shielded: US $ 74/ea[/size]
[size=x-small]- just with a core band and mounting hardware: US $ 53/ea[/size]
 
[size=x-small]If a few guys are interested, then I'll ask Richard to assign a part number to each version and then you can just contact him to tell him you want the p/n: **** trafo for the EHHA, then provide your address to determine shipping, he'll send you a total, and your off[/size]. 
 
I'll wager these units are about 3-1/4" in diameter and about 2" high, but I've asked for the dimensions.
 
So, the $53 unit will be smaller than two Hammonds and probably not hum or vibrate like the lower end Hammonds are prone to doing.  Edcors would be another alternate choice for E-Is too, but I haven't looked at their options. 

 

[BoilermakerFan]

I was close, but had them mixed up a bit...
 
The dimensions:
 
[size=x-small]-non encapped:    OD: 3.5" x HT:1.1"[/size]
[size=x-small]- encapped in box: OD: 4  1/8"  x  HT: 2 1/8" [/size]

 

[keyid]

Been awhile since picking up the soldering iron and ready for another project. Put me down for a set of stereo boards.

 

[fishski13]

i called A.L.:
Y236001 = $20.23
Y236107 = $22.47

 

[jdkJake]

 
Quote:

 

Lead times from SumR are generally about one week with encapsulated units.  Less with the open, banded units by two days or so.
 
Here is the pricing for 120/240 primary, (2) 60VCT @ 200mA, and (2) 7V @ 500mA:
 
[size=x-small]- fully encapsulated and shielded: US $ 74/ea[/size]
[size=x-small]- just with a core band and mounting hardware: US $ 53/ea[/size]
 
[size=x-small]If a few guys are interested, then I'll ask Richard to assign a part number to each version and then you can just contact him to tell him you want the p/n: **** trafo for the EHHA, then provide your address to determine shipping, he'll send you a total, and your off[/size]. 
 
I'll wager these units are about 3-1/4" in diameter and about 2" high, but I've asked for the dimensions.
 
So, the $53 unit will be smaller than two Hammonds and probably not hum or vibrate like the lower end Hammonds are prone to doing.  Edcors would be another alternate choice for E-Is too, but I haven't looked at their options. 

I am still interested. Might kill me in shipping though.
 
EDIT: Deleted obvious question -- doh!!