abbey road d enfer said:That was known to me as the 400 000 rule (20Hz-20kHz, 40Hz-10kHz...). I've seen variants.
You asked and I answered...squarewave said:OMG JR. Yes, Mackie kicked you in the balls. Get over it.
why would that make me feel better... ?If it makes you feel better, I sincerely doubt it had anything to do with the circuitry.
The problem was not the pro community, ironically Peavey actually got more respect from objective professional users. It was the wannabe/posers who were too cool to be seen using PeaveyThe problem is that the Peavey brand never got a ton of respect from the pro-audio community.
Uh... I literally invested decades into this so I have some observations. Inexperienced consumers do not want to be embarrassed by their purchase, they don't want to think they made a bad choice.People are fickle. They buy stuff because of how it looks. How it works is important. It has to work. But as long as it does, it's actually secondary to how it looks.
wow... don't get me started on that... The old logo known inside Peavey as the "lightning bolt" logo, was designed by Hartley on his notebook cover when he was in HS, and it looks like it. Everybody hated it except Hartley. Many of us inside preferred the new "block logo" much more modern looking and promising to not be your daddy's Peavey. Near the end of my time working in product management I was about the last PM using the new logo while every other PM had switched back to the lightning bolt logo because of threats from Melia Peavey (RIP) to not even show the new logo to Hartley for approval.If they just changed the logo alone that would have boosted sales literally 100%.
it depends in which stores... Back then Peavey had limited distribution, and winning a Peavey dealership was like a license to print money, so Peavey enjoyed enthusiastic dealer support from Peavey dealers, disdain from those who were not authorized dealers.The Peavey logo looked out-dated by ~1986 (and IMO it was never cool). I grew up in the 80's when Peavey stuff was high profile in the stores.
Peaveys problem was not image but being stuck in a dealer centric business model. That (bricks and mortar) is even more obsolete today, but the wheels were falling off it even back then.I still have a Renown 400 buried in my mom's attic somewhere. My impression was that Peavey stuff was popular for PA applications and cheap guitar amps. If you needed some watts, you get some Peavey stuff and put it in the background. People also get bored easily. So some new thing comes out and all of the sudden it's all-the-rage. You never had a chance.
squarewave said:Well the schems are all on the Mackie site (which is fantabulous BTW and one of the reasons why I just recently
stolebought a basically mint 1402VLZ4) and indeed I can see that early on the caps were a little small. In particular, the Micro Series 1402 VLZ used 4.7R / 470u for a cutoff of 72Hz. But later models it seems they abandoned the idea and went whole-hog for 3.32R / 3300u. Personally I think they should have kept the 470u. LC would only kick in at the very end of the pot travel.
Yeah it looks like they didn't start doing CFIA until around 1998 with the "VLZ PRO" series.Dualflip said:Thanks for the tip on Mackie schematics, I just checked the VLZ1402 schematic, the mic pre doesn't have global negative feedback, its just a CFP with an opamp.
Yup, the topbox powered mixers were under my Mixer engineering group. That was a thousands per month SKU back in the day. There were multiple generations of the iconic XR600, I think I was over the xr600"E" generation redesign.Gold said:In the 80’s Peavy made stuff others didn’t. Who else made a PA head with a couple of aux sends, EQ and reverb?
The 5150 guitar amp designed for/with Eddie Van Halen was well respected, but the cheaper "classic" series tube amps did not suck, but I am not a tube guy. The former Peavey engineer (James Brown) who worked on the 5150 design is now at Fender over the EVH series there.I remember liking a bass. The T40 was a nice bass. I just saw they go for a lot on reverb so I guess I’m not alone.
Some really nice tube guitar amps as well.
Rectifiers and 4700uF? That doesn't make sense. Post a schematic with part numbers. If you don't have schematic capture software, just draw it on a piece of paper and take a picture with your phone. If the schematic is detailed and includes part numbers and grounding layout, I can almost certainly identify the issue.Aleguitarpro said:A little update about this project.
I started testing old designs (that corp1512) with SMPS .
I can share the module I used (by meanwell) but is well dimensioned and I have a loud noise at max gain setting I can't remove.
I used a standard lm317/337 with about 4700uF caps after rectifiers (before lm317/337) and the circuit works as it should.
What I missed?
What do you mean "well dimensioned"?. SMPS are supposed to be used at no less than 20% load. If you use the tiniest Meanwell SMPS, it's a 15W type. Powering a THAT 1512 would load less than 1%. The SMPS would be in permanent hiccup mode.Aleguitarpro said:I started testing old designs (that corp1512) with SMPS .
I can share the module I used (by meanwell) but is well dimensioned
I do that more and more. I always complement them with CLC filters and linear regulators.Someone tested a preamp like this with an SMPS with good results?
abbey road d enfer said:Powering a THAT 1512 would load less than 1%. The SMPS would be in permanent hiccup mode.
squarewave said:Rectifiers and 4700uF? That doesn't make sense. Post a schematic with part numbers. If you don't have schematic capture software, just draw it on a piece of paper and take a picture with your phone. If the schematic is detailed and includes part numbers and grounding layout, I can almost certainly identify the issue.
abbey road d enfer said:What do you mean "well dimensioned"?. SMPS are supposed to be used at no less than 20% load. If you use the tiniest Meanwell SMPS, it's a 15W type. Powering a THAT 1512 would load less than 1%. The SMPS would be in permanent hiccup mode.
I do that more and more. I always complement them with CLC filters and linear regulators.
Add some load on one of the rails and see what happens. It's the total load that counts.Aleguitarpro said:I used a RPT-60C because I need 5V for digital microcontroller.
+15V rated at .1-.65A
-15V rated at .1-.5A
Total load in circuit is about 195mA on +15V rail so over 20% of load of SMPS (I have other parts not only that 1512).
That 1512 preamp circuit is separated from the rest of the circuit in which I have relays and leds.
The -15V rail is underpowered because it supply only That1512+THAT1646 and 3x TL074+3x Ne5532.
Probably it causes the noise.