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Spectrol 148-149 vs 248-249 pots

2004-01-25 by Richard Brewster

This is cross posted to both the MOTM and Oakley lists.

I have been using the Spectrol 148-149 series of pots (as used in MOTM)
for my DIY modules. The 248-249 series (Mouser catalog page 406) pots
have almost identical specs, yet are about 3/4 the price. The 248-249
series are physically smaller (.3" body depth vs .45").

It isn't clear from the specs in the catalog what makes the 148-149
series so much better. Anybody know?

It appears that the 248-249 pots are physically compatible as far as the
PCB pins location and could be substituted into a board designed for the
148-149 series. The reverse might not be the case, since the 248-249
series are not as deep and a board designed for them might have other
parts sitting closely behind that could interfere with the deeper body
of the 148-149s. Is this correct?

Thanks,

Richard Brewster

Re: [motm] Spectrol 148-149 vs 248-249 pots

2004-01-25 by Paul Schreiber

> It isn't clear from the specs in the catalog what makes the 148-149
> series so much better. Anybody know?

Spectrol 248/249 parts are 100% plastic construction (not the resistive element,
the physical part). This means plastic shaft and worse, plastic *threads* . NOT
RECOMMENDED. Also, the rotational torque of the shaft is *very* stiff.

Tried them for 1 run of 1 module, they were not suitable. Stripping of the leads
is VERY EASY to do.

Paul S.

RE: [motm] Spectrol 148-149 vs 248-249 pots

2004-01-25 by John Loffink

The 248/249 shafts are metal. Only the threads are plastic. I haven't had
a problem with the plastic threads stripping but it is true this is always a
risk.

Rotational torque on the shaft is significantly stiffer than the 148/149s
and is about the same or slightly less than the torque on my Serge, Wiard,
Oakley (Omeg pots) and Synthesizers.com pots. This may or may not bother
you.

John Loffink
The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com
The Wavemakers Synthesizer Web Site
http://www.wavemakers-synth.com

Show quoted textHide quoted text

> -----Original Message-----
> From: Paul Schreiber [mailto:synth1@...]
>
> > It isn't clear from the specs in the catalog what makes the 148-149
> > series so much better. Anybody know?
>
> Spectrol 248/249 parts are 100% plastic construction (not the resistive
> element,
> the physical part). This means plastic shaft and worse, plastic *threads*
> . NOT
> RECOMMENDED. Also, the rotational torque of the shaft is *very* stiff.
>
> Tried them for 1 run of 1 module, they were not suitable. Stripping of the
> leads
> is VERY EASY to do.
>
> Paul S.
>

Re: Spectrol 148-149 vs 248-249 pots

2004-01-26 by strohs56k

--- In motm@yahoogroups.com, "Paul Schreiber" wrote:

Show quoted textHide quoted text

> > It isn't clear from the specs in the catalog what makes the
> > 148-149 series so much better. Anybody know?
>
> Spectrol 248/249 parts are 100% plastic construction (not the
> resistive element, the physical part). This means plastic shaft
> and worse, plastic *threads* . NOT RECOMMENDED. Also, the
> rotational torque of the shaft is *very* stiff.
>
> Tried them for 1 run of 1 module, they were not suitable...

I have (or rather I had) a module with these 24x series pots. (I
bought this particular module used so it could have been from an early
production run.) They were definitely stiff! I disliked the feel
enough to call Paul and ask about these. I ended up buying a few 14x
series pots from him to rid myself of the 24x types. (Which is why I
say had. I still have the module but it doesn't have 24x series pots
in it anymore ;)

seth

Re: [motm] Re: Spectrol 148-149 vs 248-249 pots

2004-01-27 by Richard Brewster

Thanks for the replies. You all told me what I needed to know. I did
not know about the plastic vs metal bushing or the difference in feel.
I've decided to stay with the 148-149 series for my projects.

-Richard Brewster

strohs56k wrote:

Show quoted textHide quoted text

>--- In motm@yahoogroups.com, "Paul Schreiber" wrote:
>
>
>>>It isn't clear from the specs in the catalog what makes the
>>>148-149 series so much better. Anybody know?
>>>
>>>
>>Spectrol 248/249 parts are 100% plastic construction (not the
>>resistive element, the physical part). This means plastic shaft
>>and worse, plastic *threads* . NOT RECOMMENDED. Also, the
>>rotational torque of the shaft is *very* stiff.
>>
>>Tried them for 1 run of 1 module, they were not suitable...
>>
>>
>
>
>I have (or rather I had) a module with these 24x series pots. (I
>bought this particular module used so it could have been from an early
>production run.) They were definitely stiff! I disliked the feel
>enough to call Paul and ask about these. I ended up buying a few 14x
>series pots from him to rid myself of the 24x types. (Which is why I
>say had. I still have the module but it doesn't have 24x series pots
>in it anymore ;)
>
>seth
>
>
>
>
>