[dsound]

Two weeks ago I picked up a PCB + Chassis plate from Parks Audio.  I decided to build this amp because to me it is a bridge between my current Bottlehead Crack and a full-blown DIY-amp.  I don't have the time or experience to go the full DIY route, so the Budgie SE appealed to me.  The other reason why I went with this amp was I wanted to start getting into loudspeakers; while the Budgie SE only puts out 3W from a 500mV source, I think a pair of high-efficiency speakers (like the Blumenstein Orca) would pair well with the amp.  Oh yeah, it has a headphone-output too

.
 
My Background: 
My experience with electronics is quite limited but I've completed a couple projects (Joystick modding, Bottlehead Crack); I figured the Budgie SE would be a great way to learn about circuit diagrams and amp design. 

 

[dsound]

Build Progress
Here is a pic of the unpopulated PCB (pic taken from fleaBay Listing):

 
Here is the top-view of the chassis-plate that is included with the kit (note the Gold labels):

 
Bottom-view:

 
 
 
So far, I have stuffed all the Resistors into the PCB earlier this morning and will finish the rest of the PCB tonight.  The creator of the amp, Shannon Parks, was thoughtful enough to attach links to Mouser for the necessary parts. All components are well-labeled on the PCB.  The PCB itself is well constructed, I never felt like I was going to lift a pad off or mess up the traces, even with my horrible soldering skills.
 
Partially stuffed:

 
Completely Stuffed

 
 
 
 

 

[dsound]

Update 7/27/13

---

 
Mounted PCB onto the Top Plate.  Also installed ALPS pot, Speaker Jacks, Headphone Jack etc. etc.
 
 

 
Here's a test fitting on-top of the case (note the sad-holes where the Edcor transformers will eventually go 

):
 

 
 

 
I'm really digging the look of this amp.  The Edcor's usually take 5wks to arrive... time to wait.
 
 
 

 

[dsound]

Reserved
 
 
 
 

 

[dsound]

Having a blast putting this amp together.  The soldering was a snap and so far, the chassis-assembly has not been too bad.  Updated previous posts with new pics!
 
I'm excited to try the completed amp with my HD600 as well as more power-hungry Planars and Orthos.
 

 

[dsound]

Edcor transformers came in!  Wired them up yesterday.  I think I may have mis-wired the ALPS RK27 pot though because my HF jack is making this horrific sound!  Time to troubleshoot! 

 

[nikongod]

Neat amp, can you describe whats wrong with the sound? 

 

[holland]

neat looking half kit.

 

[dsound]

Quote:

Neat amp, can you describe whats wrong with the sound? 

 The issue occurs when I have both EL84 tubes inserted, when both are inserted, there is a high-pitched hum that is audible without any headphones/speakers plugged in. When I insert Headphones, the high-pitched-hum (from both channels) plays through the headphones and is very loud.

The strange part is this high-pitched hum completely disappears when either one of the EL84 tubes is removed. Music plays fine, no issues

I've checked all my solder-points and they seem good but there's obviously something that I'm missing.  
 
I'm a newb at this so any advice is welcome!
 

 

[dsound]

Quote:

neat looking half kit.

Thanks!  I think it looks really polished, here are some pics of the completed build:
 
 

 

 

 

 
 

 

[holland]

Quote:

 The issue occurs when I have both EL84 tubes inserted, when both are inserted, there is a high-pitched hum that is audible without any headphones/speakers plugged in. When I insert Headphones, the high-pitched-hum (from both channels) plays through the headphones and is very loud.

The strange part is this high-pitched hum completely disappears when either one of the EL84 tubes is removed. Music plays fine, no issues

I've checked all my solder-points and they seem good but there's obviously something that I'm missing.  
 
I'm a newb at this so any advice is welcome!
 

 
The transformers are squealing?  It sounds like something is oscillating (and not stable).
 
Just to be clear, when you remove one EL84 the sound goes away.  One channel is audible, the other is silent.  If you plug it back and you pull the other tube, it's still silent and you get music out of that channel too.
 
Do you have polarity swapped on the transformer(s)?
Can you remove feedback from the amp (output of transformer to cathode of the 12AX7) and see if it's still oscillating?
You probably might need a Zobel network to mute the oscillation.  It's hard to tell without some form of measuring equipment.

 

[dsound]

Quote:

 
The transformers are squealing?  It sounds like something is oscillating (and not stable).
 
Just to be clear, when you remove one EL84 the sound goes away.  One channel is audible, the other is silent.  If you plug it back and you pull the other tube, it's still silent and you get music out of that channel too.
Yes, this is what is happening
 
Do you have polarity swapped on the transformer(s)?
Can you remove feedback from the amp (output of transformer to cathode of the 12AX7) and see if it's still oscillating?
You probably might need a Zobel network to mute the oscillation.  It's hard to tell without some form of measuring equipment.
I checked the polarity on the transformers and the seem to be correct.
I can try to remove the feedback from the amp tonight.  Thanks!

 

[holland]

Unfortunately I don't have much experience in this area.  I'll defer to nikongod.  I would also try to pull the transformers further apart (remove from chassis), although I don't think transformer coupling registers in that way.  Just don't electrocute yourself.

 

[dsound]

Problem solved!  Turns out it was an issue with the wiring to the speaker-taps.  Beautiful music playing through both channels now.  
 
Tonight, I'll try to do a more serious listening session (and possibly take better pics too)

 

[holland]

Quote:

Problem solved!  Turns out it was an issue with the wiring to the speaker-taps.  Beautiful music playing through both channels now.  
 
Tonight, I'll try to do a more serious listening session (and possibly take better pics too)

 
Cool, figured it was something about the transformer wiring.
 
How's the gain on this thing?  It mentioned 500mV input to reach full gain, which I presume it means it clips beyond that.  I figure gain is about 10x?