Bgw amp plus eq for free!

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Hi SEAWOLF,

Thanks for your BGW input here. The 750 is indeed a beast, too large and heavy for my needs though.

On the other hand people here rarely talk about the original Crest Audio P-3500 with similar assets but in a two rack space unit. That also made some waves back then (late 70s-early 80s, long before it was purchased by Peavey) specially in the Touring market regarding rack space use on the road: packing more power in less space...

I'm already a convinced soul with regards to older BGW gear, 38 years of enjoyment on my part is a pretty long time... Same for the Spectro Acoustics preamp and EQ I had.

As for the newer Ashlys coming, well my post # 12 here did mention "Not sure though the newer amps will last as long as the BGW." Ashly usually makes good gear but my impression is i don't think they'll match the built like a tank of older BGW equipment in terms of longevity and reliability... The good old days seem gone. We'll see down the road how Ashly does.

Regards,

Richard

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To complement a previous post some pictures follow of the smaller Mackie mixer mentioned earlier.

I purchased it new around 1996 (have the invoice in my papers), I'm the sole owner the mixer ever had, and its never been out of the house, nor on the road.

When its not being used the mixer is kept in a zippered pouch seen on a pic to prevent dust accumulation. It has no visible scratch nor dent. For a 22 year or so mixer its pretty good looking.

One close picture shows the genuine Neutrik connectors provided at the time, which more recent units don't have (no name ones are used) and the potentiometer knobs have also changed on recent ones for example. For a while the mixers have been made in low-cost manufacturing China, contrary to older ones like this Made in the USA.

On the back panel the channel inserts shown can also be used as direct outs, as indicated in the manual. For picture taking purpose I covered the unit's serial number on the back, as is often done for pics, simply to prevent any misuse.

The construction is metal all around, better for RFI rejection. No plastic here contrary to what I've as seen on some more recent mixers of many brands. Like others Mackie isn't today what it use to be...

One interesting aspect of having a mixer is the "patchbay" section where many pieces of equipment can be connected and routed/assigned different ways based on what one wants to do.

Some time ago it had a few potentiometers with a slight static noise which I cleaned with Caig's Deoxit fader F5.

Richard

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Forgot to mention.

There is no dedicated PFL (pre-fader listen or cue) on this model but I've done it many times with the mixer. Just need a little creativity with what's already there and it works. If need be I can show how it is done.

The headphones jack is a Mackie special and totally independent of the Master "volume" with its own control. There's enough clean juice on the phones output to even drive a separate PA or Monitor speaker amplifier. Yep! Its in the manual:

"Serve as a totally isolated, high-quality output for a second tape recorder or PA system. Instead of using a low-cost "headphone amp" chip, we use a high-current version of our main output amplifier, which is why it can really clean out your cochlea if you crank it up too far... but still a very clean signal source." (P. 9)

Naturally, using this headphone output with its own control to drive a separate system (in addition to main out) would require purchasing ready-made or the making of appropriate cables/connectors: 1/4" stereo plug on headphone jack end, and two connectors of some variety at the other end for right and left channel inputs, depending on type of EQ or Amp inputs available at the other end: XLR, 1/4", RCA, Barrier strip or Euroblock.

May not be balanced though. Depending on what material you have on-hand or available, two mic type cables may be too large together to fit correctly in some 1/4" stereo connectors. Then, try instead installation wire with foil shield and drain wire as I use in the rack, it usually has a smaller outer diameter than mic cable.

Richard

P.S. I seem to remember, right or wrong, that at one point in time Switchcraft made a 1/4" connector with a larger entry to allow use of larger cabling...

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I had a QSC 1100 amp repaired. I sent it to the Canadian importer/distributor of the brand here thinking they know best, right? The amp has a turn-on delay, it was defective, making a loud Buzz sound upon turn-on. They "fixed" it (buzz gone) and gave it back to me. The amp works and plays music.

But since that repair, I noted the heatsinks get unsusually warm/hot, even when nothing is connected to the amp, input or output! No speaker cables, no input cables connected, just the AC cord plugged and amp turned on, I can't keep my hand on the output transistors/heatsinks very long...

So I sent it back to these guys with explanation and mention it wasn't like this before the initial repair. They told me they adjusted the amp's bias, amp is ok, the heat is normal and its like that! Not admitting any issue created. Could it be a defective replacement part, or a solder/wire creating some short for example?

Not being a repair technician I've put the three such units I have side-by-side, cover off, trying to spot any notable problem or difference(s) that may explain the situation, but its not evident. I do see slight things not being the exact same but maybe they're not enough to explain things, and these could be manufacturing related as they were not all purchased the same time.

For sure the distributor is out of luck with his explanation, having three such amps, its easy to compare the heat made by one vs the others. With the same operational conditions the other two run dead cold! Moreover, there's no sign that these two units would then be the defective ones according to their logic!

This situation reminds me of another: I seem to remember a recent post from Barry where I think he mentioned he was about done with "repair shops". I'm pretty done with this one. They SHOULD know better. Sounds pretty much like "you go in there with a problem and come out with another one". I thought the grass was greener on the US side.

Sending it to QSC in California for expertise/repair would unfortunately be pretty costly, and they would probably refer me back to the local distributor who has exclusive rights/obligations, plus "factory repair service", for the product in my country, as I was told previously by another maker regarding its local distributor.

The heat related protection circuit hasn't triggered yet (spec sheet 90°+ C, service manual 105°C, will try to measure this temperature with a thermometer). Why bother then? Heat, at the level I feel it and in this setup isn't normal, also its a well-known enemy of electronic circuitry/components. Plus I'd like to keep this small versatile amp for many more years. They were relatively expensive back then for one rack space (895. CAD retail + tx), are compact size, nicely made, perform well and quite flexible: XLR Switchcraft, 1/4" TRS, Barrier strip, DIP switches, Octal sockets, can do 8/4/2 ohms, have a couple of db of dynamic headroom, etc. and made in good ole USA.

So, back to another repair shop next week, hopefully to find out what goes wrong. Since they repair mostly Pro stuff/high level gear, and are authorized service center for most Pro brand electronics (including JBL, probably QSC too), I figure there may be hope...

On a more positive note, all my new audio gear has finally arrived (took a month+ all together), same place where the QSC is going for diagnosis and repair. Four items had arrived about 2 wks+ ago, however six others were back order at the Canadian distributor(s) involved (Ashly, DBX, Tascam, AT, etc). Quite surprised by the delays considering there's nothing really complicated or unusual on the list. This may be a sign that local distributors stock more lower cost items or fast movers only and order the others from manufacturers as required. Doesn't look good for the Lowell rack (USA made, pricier vs size) I want to order when picking up the new gear...

Richard

P.S. I'll post a picture soon of the three QSC brothers side-by-side on the "examination table".

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Here are the pictures of the amps together for comparison and examination purposes. I've also added a pic of the TR3a bias adjusment setting (about in the middle of the second closer pic). As shown by the arrow on top of it, its set at about 9 O'clock and the three amps have the same setting within a very tiny margin. Which makes me feel the heat is probably not an issue related to the bias setting, as implied by amp distributor, otherwise the other two amps would overheat as well and they don't...

I thought using a thermometer for cooking, which has a larger temp scale, normally up to around 400-500°F (as wife confirms), to monitor output device temperature of offending amp, but she can't find it.

Other thermometers on-hand practically useable here are to measure human body temperature which have more limited scale...

The no input/no output plugged temperature of an output transistor was measured at least at 44°C/111°F at which point the digital thermometer shut down because of excessive heat. It was climbing fast and no doubt it would have gone higher at that rate.

Richard

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If you can hold your hand on something, uncomfortably, but indefinitely... that’s on the order of 50°C. If intolerable after a few seconds, then closer to 60°C. If burned, perhaps use a different form of temperature estimation ...certainly sounds abnormal for an idle class ab amp. Good luck with the new shop!

Here are the pictures of the amps together for comparison and examination purposes. I've also added a pic of the TR3a bias adjusment setting (about in the middle of the second closer pic). As shown by the arrow on top of it, its set at about 9 O'clock and the three amps have the same setting within a very tiny margin. Which makes me feel the heat is probably not an issue related to the bias setting, as implied by amp distributor, otherwise the other two amps would overheat as well and they don't...

I thought using a thermometer for cooking, which has a larger temp scale, normally up to around 400-500°F (as wife confirms), to monitor output device temperature of offending amp, but she can't find it.

Other thermometers on-hand practically useable here are to measure human body temperature which have more limited scale...

The no input/no output plugged temperature of an output transistor was measured at least at 44°C/111°F at which point the digital thermometer shut down because of excessive heat. It was climbing fast and no doubt it would have gone higher at that rate.

Richard

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Hi Grumpy,

Thanks for the input on the 50° and 60° sensation benchmarks. I didn't know these. Definitely feels more like 60+ than 50°...

In my view, the distributor's tech went for easy way out the door with amp bias adjustment, probably to move on to the next waiting repair job, not wanting to go on a "fishing expedition" trying to find where that heat problem comes from...

Hopefully this won't become an expensive running bill at $75/hr. Though I like this versatile little amp, if troubleshooting/repair seems to be going the pricey way, I'll stop the bleeding, and consider instead getting another similar Ashly amp in the near future. Regards,

Richard

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At last, my new toys have finally made it to their permanent residence. Picked them up yesterday, they are now lined up in their box in the basement for the time being, a few pictures to follow. I also got for the asking a small bag with a dozen and a half of various Euroblock connectors, which I never needed before (used mostly Neutrik or switchcraft XLR/1/4" connectors), but now Euroblocks appear everywhere (e.g. on my new Ashly amps, there may be some already in the boxes, which I don't know, some spares then!).

It will take some time to set up all the gear, more so since I need to pull out of the present rack a number of items to make space, reorganize everything, make many cable/connector sets and wait for a new rack... Some cabling is easier to reuse on something else, like those for the BGW amps given away, by simply changing the XLR Pin 3 hot connections to the present standard Pin 2 hot.

The easiest device to try quickly is probably the Rolls Sonic Maximizer (XLR/RCA), not rack mount, which I can plug fast in my hi-fi setup using RCA cables, between an Onkyo preamp and a NAD amp. A few things strike me about this not expensive "sonic magic" toy: Glass epoxy PC board, Pro grade connectors, silicone damped pots, subwoofer output with 18db/oct, USA made, vs tons of cheap throw away type of stuff from Asia. I guess there's still hope south of the border...

I did order at the same time, with a small deposit, the nicely US built 7 RU rack from Lowell (LDTR-718). Its all good metal construction (no cheap particle board here) appears being made to last forever, which I tend to like. The plan is to make a plywood base under the new rack to lift it up, put the new Allen & Heath mixer on top of that rack to end up at about waist level and it will sit next to the taller rack. Still need to figure out a logical way of spliting the equipment between the two racks though, this affects cabling length. Power (AC) distribution is another matter I need to tackle here...

As more or less expected in post # 20, the new rack is... not in stock with the Canadian importer/distributor! The vendor confirmed to me that since the Internet purchasing craze or wave even importers/distributors (and retailers) don't keep much stock anymore, except popular fast moving items. The couple of weeks delay expected doesn't bother me too much here considering that expense will then go towards the new 2019 audio budget, as I wished. 2018 money is gone now, except for the following issue, if reasonable.

While being there, I also dropped the overheating QSC amp with one of the the repair technicians on-site for testing/repair estimate, even providing a good such unit for comparison purposes, the tech thought it was a nice idea to have a good reference on-hand to compare with, in case its needed. Plus I gave him a USB flash drive with all the QSC amp info I have (schematic, service manual, owner manual, specs, etc.). Helping him to succeed, indirectly helps me! Wasting time looking for manuals on the Net doesn't.

Finally, I got a nice price (only) on the Rolls studio amp (RA 200, MOSFET, etc.) mentioned previously. Better than expected, but I want to see first the outcome on the QSC at the repair shop. This may orient or not my thinking about another amp, Ashly or a Rolls, in the new year. Rolls thinks differently and does things likewise, which I tend to like here, in addition to still making some stuff in the US.

Richard

P.S. I may post later a note I wrote recently about the mixer's choice made, sort of the control center of it all, and some issues related to it...

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[grumpy]

Looks like presents arrived just in time for the holidays!

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Hi Grumpy,

Yes, just in time... No need to wrap these as gifts though, they're all destined to the same boy who put money away, waited patiently and worked with vendors to finally make it happen with one of them.

Considering most boxes wouldn't pass through the chimney on THE day, Santa authorized that these be stored in the basement living room (not the one upstairs!), still a bit too much in the wife's way though, for now... "Trespassing" again (LOL), as I already put temporarily other audio stuff in that room, since my dedicated audio room is sort of upside down at this time with all the changes I have to do. Will get there one day! Regards,

Richard

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