C-Audio Pulse 2x1100 - identifying mods

Just pop the lid off and take a good picture (good res) of the inside & post it on here & i will check for you. There are a number of mods that will need to be done, some may have been already done and others may not have been.

I have all the FULL mod kits for all the pulses including an updated professionally wound toroid pulse transformer (below).






Edited by simonp1100 - 16 December 2017 at 6:27pm

Looks like most of the mods have already been done (including the capacitor ones). The only ones i cannot see are the following:--

1. Inductor mod around the big yellow SMPS transformer BUT later updates on the PCB board had this mounted under this transformer (you need to check this) & if not then this will need to be done as well.
2. Pulse transformer updated to toroid type.
3. The four transistors near the pulse transformer need to be checked & should be ZTX651 & ZTX751.
4. The following also need to be checked:

R109 & R138 = 100R.
R232 & R250 = 56R.


If the output is distorted and unable to drive, either positively or negatively (Halfwave output)
with DC present on the output and a clip light showing whenever a signal is being heard (due to the spread of parameters in the transistors on the input stages of each channel driver).
then the below transistors also need to be changed.

TR30,TR31,TR35 & TR36 = 2SA872A.
TR32,TR33,TR37 & TR38 = BF422.

Hope this helps

Hi ,

The inductor mod is already there (this was updated and added L4 on the next generation PCB board). The ZTX transistors will need updating as well as the pulse transformer. I have PM'd you as well.

Simon

The amount of modifications depend on the version number of the main Pulse PCB board, hence some Pulses need more than others. Once the main board is out of the casing, most of the mods can be done very quickly.

I normally just take out all the relevant components, clean out the solder as well as cleaning of the residue flux on the board and then just fit all the mods in one go.

Edited by simonp1100 - 17 December 2017 at 7:03am

Just out of interest, to have these serviced and all mods completed. How much are we looking at please?

Jason, would you part with a pair of the Pulse amps?