So stone me... I bought a Behringer

[Rossi]

[quote author="mikka"]
..... but the turd is polishing me.[/quote]

what a beautiful image :?

Regarding replacements for the SSM2017. Those chips are certainly worth a try, but on the other hand they're not available everywhere. I think it makes more sense to look at the other parts of the circuit I described before you consider the SSM.

The BB and That chips perform superior, but I doubt they will make a noticeable improvement in the exact same circuit, which was designed for a SSM2017. You see, pin compatible does not mean 1:1 interchangeable. They will work, but the manufactures performance claims relate to the circuits in the datasheet. I recently exchanged emails with a guy from Greece (I think) who tried to modify an SPL Goldmike, which also uses the SSM2017. He put in an INA217 and couldn't hear any difference. So, if you're considering those upgrade chips, you may have to analyze the surrounding circuit and change stuff according to the BB/That datasheet circuits.

BTW: the That 1512 is meant for new designs and will require some changes in the circuit, the 1510 is designed as a direct replacement for the SSM chips.

 

[mikka]

Thanks Rossi. I appreciate your comments and I've taken note of what you suggested.

Would you leave the NP electrolytics alone, or bypass them? For some reason I feel that all those NP electrolytics in the signal path can't be healthy for tone.

.....

What I'm saying is that once you've bypassed the electrolytics with 100nF polyesters, there's not much difference between expensive "audio" types and run-of-the-mill standard types.

But yes, get low-esr whenever you can - they're not much more expensive than the standard types.

Jakob E.

:roll: :roll:

http://www.groupdiy.com/index.php?topic=1929&postdays=0&postorder=asc&highlight=electrolytic&start=30



I guess that what "search" is for ........... I think I've found enough info for now..... thanks to everyone who contributed or stoned.....

Now I'll suck it and see.... gotta try to remember to unplug before I get my mouth on that juicy connection

 

[mikka]

Interesting...... looks like Behringer have bypassed 2 of the non-polar caps/channel in the line section with .047 Wima caps .... ...... and two in the mic section with .068. Enough out of me for now ..... time to stop chatting and start planning and doing.

 

[mhelin]

[quote author="Rossi"]
BTW: the That 1512 is meant for new designs and will require some changes in the circuit.[/quote]

Only difference is in the gain structure where you either need to add an extra resistor or replace the pot:

http://www.thatcorp.com/datashts/dn138.pdf

1512 is available here: http://www.profusionplc.com/

 

[Snatchman]

I had this same pre modded and it turned out quite nice. The guy that modded it used Burr/Brown's to replace the 2017s with. I didn't go the transformer output option, tho' I'm concidering it now! I compared it with my Presonus Digi-Max LT pres, and even tho' the Presonus has more headroom, the Behringer outperforms it sonically,detail wise..! ( if this is saying much for a comparison.... :grin: ).. Whats up with the lack of headroom tho?.... :evil: .... Power supply maybe?....... :shock:

 

[mikka]

.... another Behringer user.... we're taking over. I had heard that these units can sound nice. (Yeah.. it's all relative... I know). Glad to hear it from you as well.

I'm posting this for other beginners like me. At the price these units go for, they seem to be great bang for the buck ... and a good early project.(I paid a lot more than 5$ for mine. They don't come up that often in Australia, but they would usually sell for about $70-$100).. So, for other beginners....... (you other guys have worked this out long ago....)

Re: The use of electrolytics in the signal path.....

Another problem is dielectric absorption. This is a condition where a small portion of the AC voltage that passes through the capacitor is temporarily absorbed by the dielectric of the capacitor, then released a short time later, causing a smearing of the sound. The severity of the problem depends on the type of dielectric in the capacitor, and other construction details.

The problem tends to be unmeasurable with normal test methods, but can be audible. Some film dielectrics such as polypropylene, polycarbonate, polystyrene and Teflon minimize the problem. But when a circuit requires several hundred microfarads, it is out of the question to use them, both from a space and cost standpoint. A compromise approach has been to use electrolytic capacitors of the required large value, then add a 1.0μF or 0.1μF (or both) film capacitor in parallel, the theory being that low frequencies will be handled by the large electrolytic capacitor, and high frequencies (where the smearing would be most audible) will be handled by the small film capacitors.

http://www.johnhardyco.com/pdf/990.pdf

 

[TedF]

Mikka, I think what that writer was talking about (electrolytics in audio circuits) is actually the tendency for electrolytics to be slightly inductive.... all that stuff about 'absorbing the audio and releasing it again slightly later', that's so much hogwash, if it was true, I could measure it.
Using electrolytics in signal paths never bothered the great designers of the past; Helios, Neve, MCI, Cadac, they all had them. In critical places the design often called for say a 0.1uF across the elec. as a nod towards the purists, and I admit to avoiding electrolytics in signal paths where possible myself, but that's more to do with DC stability than any supposed response problems.
This sort of discussion is like the discussions about how horrid TL072s are; the reality is that used correctly in the right places there's no advantage to be gained by using a more expensive device.
(and as for mic amps, I never did like the ssm2017!) :guinness:

 

[Boswell]

It's certainly true that electolytics, along with several other types of capacitors, can exhibit dielectric absorption. This is generally only a problem when you design them into circuits where the voltage across the capacitor is changing. Sample/hold circuits and filters are examples of this, but in neither of these cases would you need to use electrolytics. The point about a.c. coupling capacitors is that they block d.c. but pass the a.c., hence the voltage across them does not change, as long as the load resistor is suitably large. This means that dielectric absorption is not a problem in properly designed coupling applications.

 

[mikka]

Edit: Sorry the last post appeared while I was writing my thesis. I'll leave it as is.


Wow... thanks for jumping in ..... :shock: I appreciate your comments..... Ignorance is bliss..... and I've been quite happy lately.

But I love a good discussion .... and now you've got me started. :grin: I'm in learning mode so it's all new and challenging.

Now this is all theory, and old theory at that..... but on page 191 of the Radiotron Designer's Handbook (4th ed) Langford-Smith mentions "dielectric absorption" as causing a delay in the full discharge of a capacitor. He states that it can actually cause a second discharge some time later...... the time being dependent on the dielectric used.

Then, on page 192 he mentions that capacitance at high frequencies is usually less than that at low frequencies......with the dry types mentioned this can mean 42%-82% less capacitance at 10 000 cycles than at 50 c/s........ and this changes with temperature. I know materials have changed........but .......

Add to this the change in impedance with frequency .....

So what is a lad/y to do? I say sod it all...... let's just bypass the little buggers and be done with it! It may only be a slight difference.... if any.... but those little improvements add up. Serious designers will know far better than I, but it's only gonna cost me an extra $5 ..... so what the hell.

Re: The Behringer..... and the SSM2017 ........yes there are far better preamps out there. But just to put things in a little purse pective.....can I buy one and refurbish it for a sum total of $100 bucks? :green: I'm open to other suggestions..........

I suspect there are a few other people like me out there. We'll dip our toes in the water, learn a little, and progress. We'll learn to appreciate and work with/improve our gear, then we'll get something better etc.

Coz at the end of the day, it's not this pre that's stopping me from getting a Grammy. :green:

:guinness: :guinness: :guinness: :guinness: :guinness:

Edit: Thanks Boswell..... your comments are noted and appreciated.

Edit: I forgot to mention to TedF ... I see the Corrs used your gear..... I once mentioned to someone how amazing the sound was on a particular Corrs track. To which he replied....."Great performance, great studio, great microphones, great cables, great mic-pres and outboards, great engineers, great production team, great mastering.....". Thanks for contributing some of your knowledge and experience to heathens like me! :!: :!: I'm a novice....... I know.

 

[rodabod]

[quote author="mikka"]I see the Corrs used your gear[/quote]

I hope you doon't mean the Irish band.... :? :roll:

 

[mikka]

Ahh... might have my facts wrong. At the US website it mentions that the Corrs Live Engineer used one of Ted's units on the Corrs lead singer.

I'm already wandering around muttering "I'm not worthy, I'm not worthy.." I'd better get off the net and go get some components. I've already ordered boards for discrete opamps for another project. I'd better finish this one first! :green:


Edit: Aah..... Rodabod.... I was wrong again. Apparently it was a bunch of highland dancers wearing woollen underpants....called "The Coarse". :green: :green: :green:

 

[rodabod]

[quote author="mikka"]
Apparently it was a bunch of highland dancers wearing woollen underpants....called "The Coarse". :green: :green: :green:[/quote]

Good! I f****g hate the Corrs!

 

[TedF]

Just so that this discussion doesn't get out of hand :shock:
The reference to 'The Corrs' (the band, not the beer) comes from some promo stuff.... On a recent tour, Max Bisgrove, FOH Engineer, used P10s on all the vocals. While I would like to claim responsibility for the vocal sounds on their albums, it wouldn't be true.
Sorry to go 'off topic' :guinness: :guinness: :guinness:

 

[rodabod]

Ted, I hold you responsible for helping the Corrs. I hope those P10s have mute switches :evil: :razz: