Hi. I'm going on a preamp mod rampage, and was wondering if anyone knew
if it made any sense to swap out the 2017s from an aphex 107 for either
of the alternatives? Thanks for the help!

In article . com,
wrote:
Hi. I'm going on a preamp mod rampage, and was wondering if anyone knew
if it made any sense to swap out the 2017s from an aphex 107 for either
of the alternatives? Thanks for the help!

No, but it would certainly be worth trying. THAT still has not come out
with a 217 replacement yet, but the INA217 should be a step up. But I
think bypassing the tube stage would help a lot more than anything else.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Just do it. Install a 8 pin machine socket and plug away. I found that
either the BB or 2019 parts are vastly improved over the 2017. I sort
of liked the 2019 over the 217, report back which you prefer.

Jim Williams
Audio Upgrades

I don't know, I wasn't planning on getting both, you know and choosing
one and wasting like 8 or ten dollars. I was hoping someone would know
for sure. I'll probably take jwillia's word for it and go for the
2019s. It looks like the THAT replacement has been on the drawing board
for years! Thanks a lot for your help.

In article .com writes:

I don't know, I wasn't planning on getting both, you know and choosing
one and wasting like 8 or ten dollars. I was hoping someone would know
for sure.

We do, but it'll cost you 20 dollars for the information.

Of course nobody knows for sure. How do we know what you'll like?


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

Don't be a cheap ass when it comes to your education. Cough up four
extra bucks and buy both. You may learn something more than 4 bucks of
insight.

Jim Williams
Audio Upgrades

As far as putting a socket in there, that would raise the resistance a
bit in the circuit, no? Anyway I just got it yesterday, and it doesn't
even have a 2017! This is revision F, maybe a redesign after the 2017s
went out of production? It's got 2 each of KA324 405B, PMI SSM221OP
S9505 N32750 C, and K347 448 chips. Anyone know which one might be the
audio opamps, and if there are any upgrades for them? Thanks again for
the help!

wrote:
As far as putting a socket in there, that would raise the resistance
a bit in the circuit, no?

Not enough to matter unless you're dealing with ultra high impedances (like the frontend of a condenser mic.)

OK, I figured out a little more.

The SSM221 is a DIP-8 dual transistor array made by PMI. There's also a
version made by Analog Deviices.

KA324 is a DIP-14 quad opamp made by Samsung. Also has versions made by
Fairchild.

M35an LF a DIP-8 Wide Bandwidth Dual JFET Input opamp made by, I don't
know, it's got a logo of two parralel lightning bolts. I know fairchild
ST, NJR and national makes versions. And here's a page that talks of
some better versions, but I don't think they will work since the input
output types are different

The KF347 448 is a DIP 14 high speed quad JFET input opamp made by
samsung. Also has versions made by Fairchild.

Most of the caps are nichicon, but I don't know if they're the best low
resistance kinds, so I might replace these too.

Any advice on any upgrades would be much appreciated, thanks a bunch!

Whoa! I opened up my 001 and it has two 2017s! So maybe I'll stick in
those 2019s!

In article .com writes:

As far as putting a socket in there, that would raise the resistance a
bit in the circuit, no?

Yes.

Would it matter in this instance? No.

Why not?

You really don't need to know.

Anyway I just got it yesterday, and it doesn't
even have a 2017!

So you wanted to modify something you didn't even have? How silly! Why
do you think you want to modify this unit? I'll bet you haven't even
listened to it yet.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

Check pinouts on that transistor array against an Analog devices
Mat-02. The LM 324 is a crap quad opamp probably used for non-audio
metering. Drop in a BurrBrown OPA2134 into the dual 8 pin dip fet amps.
The LF347 quad fet amp can be replaced with a BurrBrown OPA4134,
OPA4132. Maybe even a LT1359, check input impedances and feedback phase
compensation caps to stabilize.

The Nichicons could be the Muse series or the low impedance switcher
caps rated at 105 degrees. Use a small polypropylene film cap as a
bypass on these.

Remember: They don't work if you let the smoke out!

JIm Williams
Audio Upgrades

The specs on the transistor arrays look pretty similar. Just the pinout
is different. You think the quality is better though, and will just
drop in?
http://www.rs-components.co.uk/elect...or-Arrays.html
http://www.analog.com/UploadedFiles/...853MAT02_e.pdf
Are you saying the 2 KA324s don't need replaced because it's just used
for the signal metering?
And then the OPA2134 is a dropin replacement for the LF353N? The
pinouts look the same. It looks like it has really good specs too. And
the OPA4134 would drop in to the kf347? I don't understand what you
mean by checking the input impedences or feedback caps. The 347 doesn't
have any caps near it. The two 324s each have a 1uf 50v next to them
though, and the 353s have a 0.1uf 20% 50v ceramic cap on each side.

There appears to be 5 electrolytics per input channel, only 2 of them
are brown nichicons. They are brown 105 degree H9431. Aother one seems
generic. They're green HFQ 4D1D made in japan, and there's one blue
nichicon H9449. What do mean by a bypass? Parralel? Any specific values
recommended? What about any of the electrolytics on the power section,
should those be upgraded? Thanks so much for your help!