Hi -- thanks for your response. The oscilloscope I would just use for the Bias Adjustment part of calibration, where you feed a sawtooth wave into the A-188-1 to check for clipping, and Balance adjustment to minimise clock noise.

The Frequency Meter (is that the same as a Frequency Counter) I need for VCO offset adjustment.

From the Doepfer A-188-1 BBD replacement and adjustment procedure pdf:

VCO offset adjustment:

Remark: This adjustment is necessary if the BBD circuit is replaced and the maximum clock frequency of the new BBD circuit differs from the maximum clock frequency of the old BBD circuit (please refer to the BBD table for details). It is also necessary if a BBD circuit is inserted into a module without BBD.

• Connect clock out jack socket (BU1) to a frequency meter or oscilloscope.
• Delay Clock control at the front panel fully clockwise (maximum)
• Polarity toggle switch for CV1 center position
• Do not apply control voltages to CV1 or CV2 (or move the switches to center positions)
• Adjust the frequency with the offset trimming potentiometer P6 to at least twice the maximum clock
frequency of the BBD in question (please refer to the BBD table for details).
• Example 1: max. clock frequency of the BBD is 100kHz. In this case the frequency should read at least 200kHz (e.g. 210 kHz)
• Example 2: max. clock frequency of the BBD is 200kHz. In this case the frequency should read at least 400kHz (e.g. 430 kHz)
• Overclocking is not a problem (e.g. 300kHz instead of 200kHz) as the BBD circuit cannot be
destroyed. But the BBD is used out of it's specification and some parameters (e.g. output level,
distortion, noise, feedback behaviour) may be different from those within the specs. Beyond a certain frequency the BBD may even stop working. In this case the maximum frequency has to be reduced and the power supply turned off/on.

Will a multi-meter do this, if I can find one to borrow And how would I connect the multimeter to the module

Thanks again for any help.

Cheers,
Jon

--- In Doepfer_a100@yahoogroups.com , "therpocc" <dmitry.shtatnov@...> wrote:
>
> You need to divide clock by 32. You may try to feed the clock to clock divider module or use two audio-dividers in serie. If you do not have it or can't build it around CMOS 4024, 4020 or similar IC, you will not be able to do it with soundcard-based oscilloscope.
>
> --- In Doepfer_a100@yahoogroups.com , "codotinc" <doubleopards@> wrote:
> >
> > Howdy --
> >
> > I am not a SDIYer or electronic tech, but I would like to try swapping out my 4096-stage BBD for some other chips. The Doepfer manual describes using an oscilloscope and a Frequency Meter. I can probably find a VST oscilloscope which can do the trick, but I will still need a Frequency Meter to adjust the VCO Offset if the maximum clock frequency of the new BBD circuit differs from the maximum clock frequency of the old BBD circuit.
> >
> > The Frequency Meter needs to be able to measure up to around 430 kHz. A standard frequency analysing VST only measures in the audio range, up to about 20kHz.
> >
> > Any idea how else I can measure the frequency for the clock
> >
> > Kind regards,
> > Jon
> >
> > --- In Doepfer_a100@yahoogroups.com , "codotinc" <doubleopards@> wrote:
> > >
> > > PRICE DROP and SWAP ADDED: 
> > >
> > > For sale or trade, worldwide: 
> > >
> > > Doepfer A-188-1d 4096-stage BBD Analog Delay -- $160 ($240 new at Analogue Haven and limited edition) 
> > >
> > > Will swap for A-188-1c 2048-stage BBD, or for Dixie, v.1 or v.2 
> > >
> > > Shipping is from New Zealand. One module should be $15 shipping, which is insured but with no tracking number. Adding a tracking number costs about $45 shipping. PayPal please.
> > >
> >
>