• Please note that Audiokarma will be offline briefly for updates early on Monday morning, September 28th.

Pioneer SA7100 rebuild attempt!

patfont

patfont

AK Subscriber
Subscriber
Hi, I have been waiting to recap and go over a Pioneer unit and I saw the inside of the SA7100 and it has a very nice and clean lay out. My first stereo was the SX-727, so I was looking for some of that sound again. I am kind of doing this as a warm up for a SA9100 I would like to do next. I have done some Marantz rebuilds but the Pioneer units from what I am reading here seem to have used a bunch of transistors that are prone to failure. On the Marantz rebuilds I did there was the 2SC458's on the phono board and on the amp the differential pairs but not much more then that.
The unit I have is fully fuctional, I did my do diligence and used the search function, looking for the transistors that should be replaced and there are a bunch. I have other questions about some caps and such but would like to get this straight as this alone seems like alot.

I will put the transistor list in the next post, can some one please tell me if this looks ok, or have other suggestions?
 
Last edited:
Register to hide this ad
AWR026 B Power Supply Board:

Q2 2SC945 this is listed on the protection board as one to replace does this one need to be replaced also?

If so is it also a 512-KSD1616AGBU
Also as a note Mouser has none, I have in stock, 512-KSD1616AFBU can I use it, I think it is a matter of Hfe.


AWM027 Protection Board:

Q1 and Q2 my unit is operational so do these need to be done? If so I would use 512-KSC1845FTA (the post I saw this in lists 2SC869, my unit has 2SC857's.)

Q6 2SC945 replace with 512-KSD1616AGBU, as above can I use AFBU?
Q7 2SC1384 replace with 512-KSC2690AYS

AWF0005 B Phono:

Q1 and 2: 2SA725 replace with 512-KSA992FBU
Q3-Q4-Q5 and Q6 2SC1345 replace with KSC1845FTA

AWG016 B Control

2SA725 replace with 512-KSA992FBU Q3 Q4
2SC1312 replace with KSC1845FTA Q5 Q6

AWH021 A Amp Board

Q1 Q2 Q3 Q4 2SA726 replace with 512-KSA992FBU
Q5 and Q6 2SC1451 replace with KSC3503DSTU
 
Last edited:
awr-026 Q2 512-KSC2383YTA to-92L ecb 160v 1a .9w 50mhz 160-320hfe $0.17

awm-027 Q6 512-KSC2383YTA to-92L ecb 160v 1a .9w 50mhz 160-320hfe $0.17 preferred.
 
Hi Mark! Thanks a bunch for taking the time to look this list over. I will use the 512-KSC2383YTA at awr-026 Q2 and awm-027 Q6.

On awm-027 Q1 and Q2 should I leave them on? My unit has 2SC857's.

Also on my awh-021 Q1 Q2 Q3 Q4 are supposed to be 2SA726. Q1 and Q3 are 2SA726 which reads ok, but Q2 and Q4 are B560's did some one replace these? Should I replace all 4 with 512-KSA992FBU.

And as an FYI awm-027 Q6 2SC945 is marked Q1 on schematic.

Thanks!
 
Last edited:
On my awg-016 board there are 10 Tantalum capacitors and some are in the signal path, do you replace all of these with ecaps?

6X 10uf 25V
4X 2.2uf 25V

Thanks!
 
I have placed and order for caps and transistors. I like to go board by board and check all work before moving on.

1st up will be the P/S Board: awr-026



2SC945 is Q2

 
Last edited:
I have the P/S board ready caps are here, transistors should be here Monday so I can get going on this.

 
Here is the awm-027 before shot showing what will be replaced.



2SC945 is Q6
2SC1384 is Q7
 
Last edited:
going forward here:

Can anyone help with DC offset and idle current adjustments I can not find a SM

For DC offset can I take at speaker terminals and use the adjustment resistors at the inside of the board.

For Idle current could I attach to the inside and outside leg of the bottom resistors and then what value would I be looking at 20mv? using the outer adj. resistors?

Thanks!
 
And here is the completed Prot. Board:

I had some .22uf Panasonic ECW's here so I used them.

 
Time for the Main Filter Caps next:

I had the Panasonic THA in stock and from the front they are the same size and look of the original so it almost looks stock in that respect:

Here are the caps side by side:



Here is the bottom view of the installation:



This is view from the rear, from the front they look like the stock caps being all black.

 
ok I got the phono board done, sorry I forgot to take a before pic:




Caps are Elna Silmic II and Nickicon KZ.
 
Moving on to do the last and final board the control unit. Have to remove the faceplate as the controls are soldered to this board. I took the opportunity to replace the 2 lamp bulbs for protect and power on. I also gave all the controls and switches speaker terminals and inputs a flush/cleaning and fader lube.

 
What the heck, I am a little OCD so I did the amplifier adjustments per the SM.

I used my unwrap tool to remove 1,2,3 and 16,17,18 wires from the amp board:



Then I capped the wires:



Testing:



Amp wires were cut and restripped and then soldered on to the pins.

The idle current calls for 30mV +30/-10 it was sitting at around 27.5 for both channels I tweeked it to like 29.8 and 29.9 for the channels. Then set the offset it calls for below 10mV, I set each channel below 2mV, so all is good.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom