New buchla 208 card 12,demo sound diy or built pcb no MB mods

boops · Post by **boops** » Mon Mar 04, 2019 5:58 am

Available 40 eu the pcb

nicdro · Post by **nicdro** » Tue Mar 05, 2019 5:51 am

boops wrote:Available 40 eu the pcb

Pmd

boops · Post by **boops** » Wed Mar 06, 2019 12:00 pm

top/bottom layouts
first notes

boops · Post by **boops** » Fri Mar 08, 2019 6:26 am

a lot of important built infos added

Virusinstaller · Post by **Virusinstaller** » Sat Mar 09, 2019 9:54 pm

This is a really good mod. I'm close to finishing my easel so should come back to this soon!

boops · Post by **boops** » Mon Mar 11, 2019 4:25 pm

Thanks Welcome

boops · Post by **boops** » Tue Mar 12, 2019 11:50 am

Last infos/motherboard mod added
a few pcbs available from the first batch

captnapalm · Post by **captnapalm** » Tue Mar 12, 2019 11:54 am

I have a Mouser BOM built; my PCBs should arrive in the next week so I'll test before I share the BOM.

Karl71 · Post by **Karl71** » Tue Mar 12, 2019 2:47 pm

captnapalm wrote:I have a Mouser BOM built; my PCBs should arrive in the next week so I'll test before I share the BOM.

Thanks. Let us know how you fair.

boops · Post by **boops** » Wed Mar 13, 2019 6:46 am

captnapalm wrote:I have a Mouser BOM built; my PCBs should arrive in the next week so I'll test before I share the BOM.

thanks,which film caps did you choose ?mkt mkp etc
and which 4 x Aop U1?
u2 /u3 available at mouser
TLC081 is not TLO81 !

tlc081

OPA134

captnapalm · Post by **captnapalm** » Wed Mar 13, 2019 9:53 am

boops wrote:
captnapalm wrote:I have a Mouser BOM built; my PCBs should arrive in the next week so I'll test before I share the BOM.
thanks,which film caps did you choose ?mkt mkp etc
and which 4 x Aop U1?
u2 /u3 available at mouser
TLC081 is not TLO81 !

tlc081

OPA134

I didn't include U2 because you hadn't posted about alternatives yet so I bought NOS LME49740 from eBay.

I used the same OPA134 as your link, for TLC081 I used this one which is same as your link but wider temp range.

Film caps I used PP, various ones depending on size etc. Will check before posting the BOM.

boops · Post by **boops** » Wed Mar 13, 2019 4:53 pm

LME 49740

Karl71 · Post by **Karl71** » Thu Mar 14, 2019 2:49 pm

OPA4277 looks like a likely replacement for the LME49740. Any other suggestions.?

captnapalm · Post by **captnapalm** » Thu Mar 14, 2019 3:03 pm

Karl71 wrote:OPA4277 looks like a likely replacement for the LME49740. Any other suggestions.?

Boops recommends TL074 in the updated description.

Karl71 · Post by **Karl71** » Thu Mar 14, 2019 3:49 pm

captnapalm wrote:
Karl71 wrote:OPA4277 looks like a likely replacement for the LME49740. Any other suggestions.?
Boops recommends TL074 in the updated description.

Ahah!
I might do a comparison when I get around to the build. The OPA4277 is €9 from mouser. Im curious what the extra € 7 gets me in fidelity.

boops · Post by **boops** » Fri Mar 15, 2019 4:16 am

captnapalm wrote:
Karl71 wrote:OPA4277 looks like a likely replacement for the LME49740. Any other suggestions.?
Boops recommends TL074 in the updated description.

i ve written the cheap Tlo74 should work,i ve not recommended it,its not a really , high end aop .

captnapalm · Post by **captnapalm** » Fri Mar 15, 2019 7:08 am

boops wrote:

i ve written the cheap Tlo74 should work,i ve not recommended it,its not a really , high end aop .

You’re confusing Boops

boops · Post by **boops** » Fri Mar 15, 2019 1:07 pm

Plenty of 4 x aop work ,just check the pinout
the lme 49740 i ve choosen is great ,the tlo74 is more standard ,and the pinout works .Im a diyer ,myself,and i alway try to be in a diy behaviour,some time not so easy

Sorry for the confusion

boops · Post by **boops** » Fri Mar 15, 2019 1:15 pm

Karl71 wrote:OPA4277 looks like a likely replacement for the LME49740. Any other suggestions.?

OPA4277PA
dip14
4277
let know ,how it sounds .

captnapalm · Post by **captnapalm** » Fri Mar 15, 2019 2:04 pm

boops wrote:Plenty of 4 x aop work ,just check the pinout
the lme 49740 i ve choosen is great ,the tlo74 is more standard ,and the pinout works .Im a diyer ,myself,and i alway try to be in a diy behaviour,some time not so easy

Sorry for the confusion

We appreciate what you do

Karl71 · Post by **Karl71** » Fri Mar 15, 2019 3:49 pm

Will do, just waiting for my mouser order.

Karl71 · Post by **Karl71** » Fri Mar 15, 2019 3:54 pm

My understanding is that the audio out of this beautiful instrument can be improved on..so if someone goes to the trouble of redesigning the output card, lets go all in and spare no expense.the 208 deserves it.

boops · Post by **boops** » Fri Mar 15, 2019 5:10 pm

a few more infos

the motherboard mod is needed for a smooth control of the reverb imho

-the right jack socket is the direct audio out MO by default (or the CO if you choose it),it has a 100 % level no reverb

boops · Post by **boops** » Thu Mar 21, 2019 5:23 am

main outputs schematics added

captnapalm · Post by **captnapalm** » Sat Mar 23, 2019 12:23 pm

Here is a Mouser BOM. This does not include a quad op amp U2, IC sockets, or the J2 & J3 headers/plugs for reverb cables. I built mine with this BOM and everything works great. I only changed C7/C8 after I built mine because the form factor was big. C13 is also big but there’s room for it, and Mouser didn’t have a smaller one for that value.

https://www.mouser.com/ProjectManager/P ... 46bb3779c5

MUFF WIGGLER

MUFF WIGGLER

New buchla 208 card 12,demo sound diy or built pcb no MB mods