My name is Mike. I am new to DIY audio (have been lurking for a while). I do have an extensive EE background (20 years designing analog and mixed-signal ICs). For the past nine years I have been designing chips for TI/Burr-Brown, mostly in the communications area (DSL, now HD Radio). Sorry, I can't get samples or demo boards any easier than the rest of you can.
I've always been interested in DIY electronics ever since I built a Heathkit guitar amplifier when I was a teenager. I've just avoided hobbies that were too much like what I do at work. Now I'm thinking about stuff like tube amps, which are the antithesis of the 0.18 um CMOS designs I do for a living.
Anyway, it's great to see an introductions section on a forum. Let's see if anybody actually reads it.
Mike
"Never confuse motion with action." B. Franklin
I've always been interested in DIY electronics ever since I built a Heathkit guitar amplifier when I was a teenager. I've just avoided hobbies that were too much like what I do at work. Now I'm thinking about stuff like tube amps, which are the antithesis of the 0.18 um CMOS designs I do for a living.
Anyway, it's great to see an introductions section on a forum. Let's see if anybody actually reads it.
Mike
"Never confuse motion with action." B. Franklin
Welcome
Hi Mike,
20 years of IC-designing, woow....😱
May be you can enlighten me why a good discrete design sounds better than the best IC's like Burr-Browns OPA 627? [Thorsten
to my ears, in my setup, hornspeakers, my music!]
I have been thinking about distributed capacitances and junction isolated devices in the IC. But the OPA 627 is a dialectrically isolated IC!
Any insight information?
You are into tubes because of the sound?😉
Hi Mike,
20 years of IC-designing, woow....😱
May be you can enlighten me why a good discrete design sounds better than the best IC's like Burr-Browns OPA 627? [Thorsten
to my ears, in my setup, hornspeakers, my music!]I have been thinking about distributed capacitances and junction isolated devices in the IC. But the OPA 627 is a dialectrically isolated IC!
Any insight information?
You are into tubes because of the sound?😉
Welcome Mike,
I work (and play) with a mixture of very old, and (fairly) new. It's refreshing.
BTW, we have a lively tube forum, with all kinds of debate and projects going on. Please do pop over.
Cheers,
I agree there is something interesting about opposites.😉
I work (and play) with a mixture of very old, and (fairly) new. It's refreshing.
BTW, we have a lively tube forum, with all kinds of debate and projects going on. Please do pop over.
Cheers,
welcome on board mike,
what a pitty you can´t source some hundred developer boards and tons of free sample opamps for us - TI should take a look on advanced public relations methods like Passlabs practises.
But you could say me which is the BEST high voltage high current OPA from TI, for audio purpose? (not OPA512 because there are no 512 in free sample program)
Till
what a pitty you can´t source some hundred developer boards and tons of free sample opamps for us - TI should take a look on advanced public relations methods like Passlabs practises.
But you could say me which is the BEST high voltage high current OPA from TI, for audio purpose? (not OPA512 because there are no 512 in free sample program)
Till
As a general rule (and ignoring economic considerations), increasing levels of (analog) integration will lead to reduced performance. The main reason for this is that compromises are made at various stages in order to get varied analog functions built in the same manufacturing process. There are two main exceptions to this rule: (1) if low parasitics are the limiting factor in performance - usually a dominant factor in high-speed designs; (2) if high degrees of matching between devices are required to meet performance - most data converters as well as low-offset opamps.
Another issue regards correlation between "better sounding" and measurable (and "simulatable") performance parameters. There are as many theories wrt the relative importance of various performance measures (THD, IMD, TIM, etc.) as there are circuit designers. Discrete circuits can be optimized by endless and relatively painless tweaking - changing a resistor value (or composition!) here and there, trying a different transistor, etc. For an IC, every time you want to tweak the circuit it's gonna cost you at least $25K for a new mask set, plus a lot of time (months) before you can see if the tweak helped (Note: $25K is for old processes for parts like the OPA627. Masks for the latest production process at TI are >$500K.)
I don't know if I am into tubes for more than the curiosity value at this point. I guess right now I am looking into tubes because they look cool in a retro sort of way. My late father (an EE who went through the tube to transistor transition) thought I was nuts to even consider tubes, particularly SE circuits.
I can't get samples because I don't have the connections. When I need a TI part even for a work-related project, guess where I usually have to go - the samples program or Digi-Key! Unless I personally know somebody who may have some parts in their desk drawer. Demo boards are even worse - I've never been able to get gold of one for (permanent) personal use. They are quite expensive and in short supply - usually when they are sold they are sold at a loss.
How does Pass Labs' sample program work 🙂 ?
I haven't got a clue - remember, I'm new to this audio stuff. AFAIK, none of the power OPAs were designed specifically for audio, I think most of the market is in industrial automation applications (I could be wrong, OPAs are in another department).
Welcome Mike,
Besides having fun in the tube forum you might be able to lend some insites into some of the op-amp threads... the gainclone one is raging right now (and we are starting to get tubes into the mix)
dave
Besides having fun in the tube forum you might be able to lend some insites into some of the op-amp threads... the gainclone one is raging right now (and we are starting to get tubes into the mix)
dave
Welcome, Mike
We look forward to your insights in the tube forum. Just because we like valves doesn't mean we don't use the odd bit of silicon. Although I understand there are some more forthright members who take a more strict approach.
Are you intending to build a new amplifier from scratch, or rebuild your existing one?
We look forward to your insights in the tube forum. Just because we like valves doesn't mean we don't use the odd bit of silicon. Although I understand there are some more forthright members who take a more strict approach.
Are you intending to build a new amplifier from scratch, or rebuild your existing one?
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