I think the M2X design "by nature" will have zero V on output if only one rail fuse burns. I don't think you will get either + or - rail voltage on output (I have not tested it).
It was my fear that this would happen as it happens with many other amp designs (+ - rails on output).
Other may confirm if theory is correct or not.......?
It was my fear that this would happen as it happens with many other amp designs (+ - rails on output).
Other may confirm if theory is correct or not.......?
I built the Tucson yesterday. While I planned on mounting the OPA1611 in an adapter, the one I purchased was for through the hole installation and didn't fit into the DIP socket. I decided to just solder it to the board, and this was the first time I installed an SMD component. So far, this makes Ishikawa, Mountain View, and Tucson.
I need to do so much more listening! So far, I prefer the warmth and depth of Ishikawa most. Second in preference, the Tucson is quite good! It's difficult to tell without an immediate A/B, but I'm guessing I couldn't pick one from the other on a lot of material.
These are surprising conclusion, because I was convinced I'd like the single-ended nature of the Mountain View most. It presented detail in a way that was precise, but for some reason my brain didn't find that to be as enjoyable on the whole. I need to get back to it for more impressions.
I'm only a third of the way through this thread, and look forward to reading more impressions - especially from people who have tried different op amps in the Tucson. If the cost of the Toshiba/LS parts is too great for a builder or they're unavailable, I'd definitely recommend Tucson for its low component count/cost and excellent sound.
I need to do so much more listening! So far, I prefer the warmth and depth of Ishikawa most. Second in preference, the Tucson is quite good! It's difficult to tell without an immediate A/B, but I'm guessing I couldn't pick one from the other on a lot of material.
These are surprising conclusion, because I was convinced I'd like the single-ended nature of the Mountain View most. It presented detail in a way that was precise, but for some reason my brain didn't find that to be as enjoyable on the whole. I need to get back to it for more impressions.
I'm only a third of the way through this thread, and look forward to reading more impressions - especially from people who have tried different op amps in the Tucson. If the cost of the Toshiba/LS parts is too great for a builder or they're unavailable, I'd definitely recommend Tucson for its low component count/cost and excellent sound.
The five input stage daughterboards which ship from the diyAudio Store, are only the beginning. Other IPS cards that appear in this thread (see post #4) include IPS6, IPS7, and Cedarburg . The one called IPS7 may interest you, since it includes two DIP sockets rather than one. These allow you to install either a single opamp (examples: LT1122, OPA604) or a dual opamp (examples: NE5532, OPA2134, LM4562), and listen to your M2x with your chosen opamp as the IPS. For builders who enjoy "opamp rolling", this offers delightful flexibility, since some great-sounding opamps are only sold as singles, while other great-sounding opamps are only sold as duals. IPS7 also happens to include a circuit refinement which Tucson lacks: bootstrapped supply rails.
That’s an easy one… in M2x the input cards are all, by design, buffers, in order to supply the current necessary to allow the autoformer to provide the needed gain for the output stage. The buffers all float between the power supply rails as thier reference to ground isn‘t necessary for proper operation and can be utilized beneficially in certain cases.
As jameshillj correctly infers, any of the IC input cards would require a connection to ground in order to be wired for gain, and that may work just fine, but I don’t think anybody has tried it, (perhaps one person?) so an intrepid amplifier builder might as well break out a Tucson and fiddle with it and see it can be made to work properly. The worst that happens is an unsuccessful experiment and you return the configuration to (the excellent sounding) stock. And if it works, fantastic! Please post your results here.
As jameshillj correctly infers, any of the IC input cards would require a connection to ground in order to be wired for gain, and that may work just fine, but I don’t think anybody has tried it, (perhaps one person?) so an intrepid amplifier builder might as well break out a Tucson and fiddle with it and see it can be made to work properly. The worst that happens is an unsuccessful experiment and you return the configuration to (the excellent sounding) stock. And if it works, fantastic! Please post your results here.
Last edited:
What about the AKSA Lender / Melbourne input board project?
This board could be configured to have some gain?
It also had a GND connection. Maybe search this forum for "Melbourne".
Back in time there was this group buy?
https://www.diyaudio.com/community/threads/melbourne-daughterboard-for-m2x.333653/
Maybe if anyone have tried the board could give some feedback?
This board could be configured to have some gain?
It also had a GND connection. Maybe search this forum for "Melbourne".
Back in time there was this group buy?
https://www.diyaudio.com/community/threads/melbourne-daughterboard-for-m2x.333653/
Maybe if anyone have tried the board could give some feedback?
This forces me to admit I'm a board hoarder.
These are up for grabs. PM if interested.
Hi there,
I'm at the final stages of shopping for my M2X mono blocks and the enclosures I'm looking at would only fit a 250VA transformer. For stereo, 300-400VA is usually recommended, but would that work for mono? What could be the impact on the amp performance?
Sorry for the most-likely beginner question, but as the transformer and chassis are the most expensive items, I'm reluctant to experiment by myself on these parts!
I'm at the final stages of shopping for my M2X mono blocks and the enclosures I'm looking at would only fit a 250VA transformer. For stereo, 300-400VA is usually recommended, but would that work for mono? What could be the impact on the amp performance?
Sorry for the most-likely beginner question, but as the transformer and chassis are the most expensive items, I'm reluctant to experiment by myself on these parts!
Hi,
just a short question, why is it "required" to use a non-inductive dummy-load for test purposes?
I mean, on a finished amp we use complex, sometimes evil loads and they change depending on the frequency - or is it the answer? Because a dummy-load is constant and frequency-independent?
Thanks in advance.
just a short question, why is it "required" to use a non-inductive dummy-load for test purposes?
I mean, on a finished amp we use complex, sometimes evil loads and they change depending on the frequency - or is it the answer? Because a dummy-load is constant and frequency-independent?
Thanks in advance.
250VA will be fine for a single channel built to specs in the guide.
Compared to a single, stereo amp with a 400VA transformer. May have a bit less voltage sag, but that's unlikely to be meaningful. Biggest change is stereo amp in a single enclosure to monoblocks.
My
You got it. It's not strictly required, especially for hobbyists.
When standardized measurements are done for comparative purposes, publications etc. it's very helpful, if not necessary, to have a standard load. As you said, most loudspeakers vary vastly (and to a much higher degree than most resistors).
I got non-inductive resistors to use for distortion / FR / clipping etc. testing b/c they weren't that much more expensive than the ones I was planning to get anyway. Plus, sometimes we like to post / share results.
My
Others with far more skills may have more meaningful insight.