Menu

Show posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Show posts Menu

Messages - FenderDeluxe112Plus

#16
Amplifier Discussion / Re: Fender 112 Deluxe Plus
July 20, 2022, 04:57:05 AM
Checked the ac on speaker 3.59vac
It drops to 1.32 wiith a jumper from cr3 anode to ground.
#17
Amplifier Discussion / Re: Fender 112 Deluxe Plus
July 20, 2022, 04:36:02 AM
I also checked for broken pads/cracked solder and all checked out ok.

Thanks,
Andy
#18
Amplifier Discussion / Re: Fender 112 Deluxe Plus
July 20, 2022, 04:30:00 AM
Hi all,

I finally got hold of the new filter caps and had time to install them. I also replaced q9 while the board was out.

Long story short - I still have the same or similar buzz happening.

After cap replacement I checked for dc on speaker 0.023vdc

Tp1 30.05vac
Tp2 30.00vac
Tp3 39.02vdc
Tp4 -39.03vdc

Ac voltages

Tp3 0.066vac
Tp4 0.209vac


#19
Amplifier Discussion / Re: Fender 112 Deluxe Plus
June 01, 2022, 10:41:09 AM
You cannot view this attachment.

Thanks g1,

I guess either I misread or recorded the ac voltages incorrectly, or something changed after I replaced parts.

I reflowed the solder on the main filter caps and checked resistance to all connections when I originally pulled the board so will assume c48 is bad. Will order new filter caps!

Thanks again
#20
Amplifier Discussion / Re: Fender 112 Deluxe Plus
June 01, 2022, 07:43:18 AM
Just double checked ac on collectors of both tip147s
Q11 and Q2
2.34vac 2.35vac respectively.
#21
Amplifier Discussion / Re: Fender 112 Deluxe Plus
June 01, 2022, 07:38:42 AM
Tp1 30.31 vac 
Tp2 30.31 vac

Tp3 30.12vdc    00.04vac
Tp4 - 30.20vdc  02.45 vac

Tp5 16.40 vdc    00.02vac
Tp6 -16.42 vdc  00.01vac

#22
Amplifier Discussion / Re: Fender 112 Deluxe Plus
May 31, 2022, 04:40:24 PM
Have got the 100hz tone coming from the preamp out.
#23
Amplifier Discussion / Re: Fender 112 Deluxe Plus
May 30, 2022, 03:52:34 PM
Yes, am on 50hz 230v mains in the U.K.
I looked up 100hz tones on youtube and thought it sounded close.

I don't have another amp here to test it at the moment. I might be able to dig out a sampler to test it though.
#24
Amplifier Discussion / Re: Fender 112 Deluxe Plus
May 30, 2022, 11:31:01 AM
Initial ac voltages
1.72vac with jumper
4.5vac no jumper
#25
Amplifier Discussion / Re: Fender 112 Deluxe Plus
May 30, 2022, 11:28:17 AM
1.48vac with jumper to ground.
3.90vac no jumper

These are the readings that it settled at. Both readings started higher then dropped.
#26
Amplifier Discussion / Re: Fender 112 Deluxe Plus
May 30, 2022, 07:35:32 AM
Similar to plugging guitar into power amp in.
#27
Amplifier Discussion / Re: Fender 112 Deluxe Plus
May 30, 2022, 07:31:21 AM
With a jumper to ground at cr3 anode the buzz is there but quieter.
#28
Amplifier Discussion / Re: Fender 112 Deluxe Plus
May 29, 2022, 02:40:15 PM
Yes, that is the sound at switch on with nothing plugged in.

#29
Amplifier Discussion / Re: Fender 112 Deluxe Plus
May 29, 2022, 03:18:32 AM
Cr13 and 14 have a forward voltage of 0.5 which seems ok.

Reversed they read 1.9020 and 1.8064
Does that check out ok?
#30
Amplifier Discussion / Re: Fender 112 Deluxe Plus
May 29, 2022, 03:10:03 AM
Thanks g1,

Cr9-12 and cr39-42 read between 0.6 and 0.7 with a reading of 1 with leads reversed.

Cr5 -8 are within the heatsink so I can't read them at the moment - I did pull them to test when I changed the output transistors and they were good.

Agree about q9. I have a few 2n4403s so I will replace it next time I pull the board.