Rob Wright Posted August 26, 2023 Posted August 26, 2023 I have a 220 Hafler here that has been reconditioned and I love the Mosfet Amps. I was originally trying to obtain a DH500 Hafler. I wanted a BIG mosfet amp and there are some awesome upgrade kits available for the 500 Hafler. Being that they are as rare as hens teeth in Tassie, I was virtually tripping over myself when one hit the marketplace classifieds a few kilometres from home. Unfortunately the bloke that had it was off riding his bike or whatever and I was leaving for work the next day. Unfortunately when you work away from home a lot, you often miss out on some really nice things. I managed to find a DH 500 in Adelaide through a wanted to buy here but they owner had a bit of stuff going on which made my only option a Pack and Send full service pick up, pack, the lot. I'll tell you what they wanted to do a $80 plus a box freight job was absolutely prohibitive. No way, never. Another option I was always open to was a big mosfet Perreaux. The 5150 that has come up in Perth recently well, lets say I was salivating over it, but I did a bit of shopping around and it weighs 100 kg which was going to put freight at about $957. And I sort of wondered who would help me lift it. A Perreaux 6000B 300w into 8ohms was available locally but came with a big set of Fender Speakers. I have absolutely no room for anymore speakers and initially he didn't want to separate. While I was admiring the 5150 in the classifieds a message popped up on my screen that he'd found someone interested in the speakers so I could take the amp. He was only an hour away so I couldn't get in the car quick enough after we had agreed on a price that was probably $200 more than I wanted to pay and $200 less than he wanted for it. He drove a pretty hard bargain really, but the clincher was that it had been serviced before it went into storage.
Rob Wright Posted August 26, 2023 Author Posted August 26, 2023 So I popped the lid off look for any obvious signs of a service and there was a list of stuff that had been attended to in the base tray. So I was happy to part with $600 and go and listen to it. Listening to it was no disappointment. That powerful Mosfet liquid, clean, strong sound. It walks all over the 300w Emotiva it is sitting on in the photo. When the Krix Euphonix speakers started to sound a little bit stretched on the Emo, the big P just kept powering on. But it's a bit knocked about. It had been used by a band, so it has scratches and dings and dents and just does not fit in with the rest of my gear. First point of call was the screen printer to see if they could redo the artwork on the fascia. Yep. Next, the handles. Too far gone to recover with deep pits and scratches. Went to see my cousin who is the Chief Engineer on one of the big boats offshore and his Father has and welding/engineering workshop. He said he could make some, but without casting, there would be a slight radius in the corners rather than the sharp diagonal. Yep. Good. 3
Rob Wright Posted August 26, 2023 Author Posted August 26, 2023 Right, so, part of any clean up should involve a once over by my electronics guy who is three hours from home. We were going to my daughters gymnastics competition at his end of the state, so we decided to leave a bit early and drop it off on the way. He's an enthusiast who does a lot of private work and just loves it. We pulled the lid off and we were looking at the big old transformer I said "wouldn't it be cool if we got a separate box and put two transformers in there, and then run two big main caps for each channel." He paused for a second, his eyes lit up " I think we can fit two big Toroidal Transformers in there and four main caps. We just need to do (this, that and the other)." My initial plan was to get the internals done and then pull the fascia plate back off and have it powder coated and the artwork re done. He emailed me the next morning after having a look at everything and pulling it apart. with all the work and rearranging it was going to be a huge job for me to do that. We called in on the way back from the gymnastics and eyeballed it. Thankfully I would be working up there that week, so he could fully dismantle it and I'd pick it all up and get it powder coated so he could give me the finished product. 1
Rob Wright Posted August 26, 2023 Author Posted August 26, 2023 (edited) Now, this is where it started to get a bit hectic for me. The original base tray would not be strong enough for the new configuration. And the original top lid was warped a little and I knew I would wish I'd had something done about it. This is where Jason from Glasgow Engineering down in Launceston really came to the rescue. We formed a relationship with them while the company I work for was doing a major pipework job right outside their workshop. They did some work with us as part of that project that basically had to be mm perfect. Some of the work that come out of that workshop is just phenomenal, high class. Both big and small. He fabricated me up both trays out of 3mm aluminium same day service. I dont really have any good photo's of the trays as one of the other people I work with picked them up and dropped them at the powder coater for me while he was on another errand. He said they are spot on though. So I had to get a bit done over four days and thankfully everything got to the powder coater and should be finished in a week. What I was worried about was leaving a pulled apart amplifier on his bench for a month. Thanks to Jason again as that won't be happening. Edited August 26, 2023 by Rob Wright 3 1
Rob Wright Posted August 30, 2023 Author Posted August 30, 2023 So, some nice new transformers have arrived and true to the Powder Coaters word, the part are ready a week from when he stated. Launceston Powder Coating, Invermay. I've had to arrange a Courier to pick them up and take them to the amplifier wizard and things are moving along very nicely. 1 1
playdough Posted August 30, 2023 Posted August 30, 2023 Watching on with interest. I've a pair of EV P3000's with a similar set up,2 x power TX, twin PS. Nothing like brute force Power, the smell of cooking coils 2
Rob Wright Posted August 31, 2023 Author Posted August 31, 2023 20 hours ago, playdough said: Watching on with interest. I've a pair of EV P3000's with a similar set up,2 x power TX, twin PS. Nothing like brute force Power, the smell of cooking coils Thanks for taking an interest @playdough I always like a bit of headroom. The old girl had plenty when I plugged it in but there were some issues with the fan being very loud and a big thump on start and an even bigger one switching off. So no matter what it needed a once over. And the Transformer look a bit old, so I didn't want to sort everything else out and have it not survive. Thos EV p3000's certainly have some "headroom" Wow. 2
Rob Wright Posted August 31, 2023 Author Posted August 31, 2023 Assembly begins. The powder coating is spotless. White cotton gloves are still needed until it hardens up a bit or it leaves permanent marks. The feet are on the newly made tray. Now there is a lot to do. All of the work on the boards has been done which I'll explain later. Now it's time to make the bridges for the extra and bigger main caps, and fit them and the two new transformers. 1
Rustee Posted September 1, 2023 Posted September 1, 2023 15 hours ago, Rob Wright said: with the fan being very loud and a big thump on start and an even bigger one switching off I have pretty much the same amp (6000C)which was restored several years ago. Didn't go as far as dual transformers (although I did think about that mod - some info on The Factory Audio blog which you've probably already seen) but we did add the following: - Soft start - Delay relays upon start up - DC protection - by-pass the balanced stage and by-passed the attentuators - Instead of temp controlled or switched fan, we opted for a continuous slow running fan which just ticks along keeping air moving through the amp. Also had much bigger caps put it. You're probably all over those upgrades already but thought I'd mention it in case you weren't. Love my Perreaux pre and power amp Cheers, Russ 2
playdough Posted September 1, 2023 Posted September 1, 2023 16 hours ago, Rob Wright said: old girl had plenty Hi Rob yes not good when they misbehave, although looks like all those things wrong will be fixed with the rebuild. Thought I'd throw in a photo of the pair of German Classic EV's. for the big amp fans. scrolling around 1200 w x 2 ch into 4 ohms or bridged x 1 ch , 2400 w into 8 ohms designed to do 1 thing, torture speaker driver motors. They draw 500w each at idle after start up, then the fans slowly ramp up over 5 minutes as it gets (toasty) to op temp. One has an intermittent gain attenuator pot, seems ok at the moment, . I've been through them and give them a good careful clean up and look over up only, replaced the air intake filters. Quiet, luckily and stable operating. I love the sound they have, class A grip and driver control, forever. Got lucky a local backline were upgrading to SMPS D Class then complained about them. They go out occasionally on jobs so not quite shelved completely. They are a little scratched but only cosmetic damage. You have me keen to set one of these up on some spare speakers, work out the V pot issue. 2
LogicprObe Posted September 1, 2023 Posted September 1, 2023 I'm waiting for pics of these big Fender speakers!
Rob Wright Posted September 1, 2023 Author Posted September 1, 2023 10 hours ago, Rustee said: I have pretty much the same amp (6000C)which was restored several years ago. Didn't go as far as dual transformers (although I did think about that mod - some info on The Factory Audio blog which you've probably already seen) but we did add the following: - Soft start - Delay relays upon start up - DC protection - by-pass the balanced stage and by-passed the attentuators - Instead of temp controlled or switched fan, we opted for a continuous slow running fan which just ticks along keeping air moving through the amp. Also had much bigger caps put it. You're probably all over those upgrades already but thought I'd mention it in case you weren't. Love my Perreaux pre and power amp Cheers, Russ Thanks @Rustee Bypassing the attenuators makes a lot of sense. I did have the option of a speed control pot for the fan, but I decided to run with a switch. My reasoning being that the Hafler sounds better once it warms up a bit, and I would know when the fan should be switched on. Plus the pot was not cheap let me tell you, and the fan was already new from the last set of reco work. I'm not too sure how the soft start is being set up. He had some rare Burr Brown OP Amps there from another job years ago which he is installing one on my board. It's a bit of a fiddle that needs it's own small transformer, so I have been assured that it is a very well worthwhile mod. That was a big part of the reason I had to get the powder coated parts to him before the build, as fitting that stuff in around the fascia. Also, particularly the LED clipping lights, which join onto the same board was going to make it a major mission for me to get it all apart. 2
Rob Wright Posted September 1, 2023 Author Posted September 1, 2023 9 hours ago, LogicprObe said: I'm waiting for pics of these big Fender speakers! They were sold separately and I only saw those in old mates original advertisement. The steel corner edges had some signs of surface rust, which you can also see on the tray that holds the main caps on the first pics Thankfully someone else wanted them or I'd probably still be chasing one of these amps.
Rob Wright Posted September 1, 2023 Author Posted September 1, 2023 9 hours ago, playdough said: Hi Rob yes not good when they misbehave, although looks like all those things wrong will be fixed with the rebuild. Thought I'd throw in a photo of the pair of German Classic EV's. for the big amp fans. scrolling around 1200 w x 2 ch into 4 ohms or bridged x 1 ch , 2400 w into 8 ohms designed to do 1 thing, torture speaker driver motors. They draw 500w each at idle after start up, then the fans slowly ramp up over 5 minutes as it gets (toasty) to op temp. One has an intermittent gain attenuator pot, seems ok at the moment, . I've been through them and give them a good careful clean up and look over up only, replaced the air intake filters. Quiet, luckily and stable operating. I love the sound they have, class A grip and driver control, forever. Got lucky a local backline were upgrading to SMPS D Class then complained about them. They go out occasionally on jobs so not quite shelved completely. They are a little scratched but only cosmetic damage. You have me keen to set one of these up on some spare speakers, work out the V pot issue. Yeah playdough, what a pair of weapons. There were a couple of these for sale 4 hours from me at one stage. I was really keen to try them out but they were a little pricey for a try out on a whim. And yes, I'm a big amp fan and those are very big ones. I set my mate up with a couple of (class D) PX8 Yamahas on some CBR15's and 18inch yamaha subs. All pro audio gear, but still awesome sound quality for normal listening, and louder than a disco if you turn them up. It's well worth getting those looked at. If they were near me and came up at the right price I'd have to have one or both. 1
playdough Posted September 1, 2023 Posted September 1, 2023 (edited) Hey Rob, I wouldn't be surprised if these were the same ones , small World Mate ! We could have that conversation. Nothing wrong with SQ from a Pro Amp, but I lean towards the EV personally Might start a thread, do a service, show the innards. Amazing case layout. On with the 6000B job first Very interesting mods going on with it. Edited September 1, 2023 by playdough
Rob Wright Posted September 1, 2023 Author Posted September 1, 2023 (edited) 1 hour ago, playdough said: Hey Rob, I wouldn't be surprised if these were the same ones , small World Mate ! We could have that conversation. Yeah, pretty sure the ones I was looking at were in the north of Tasmania. I can't remember the price but it was a long drive as well. For sure, open it up and give us a look inside. Edited September 1, 2023 by Rob Wright 1
playdough Posted September 2, 2023 Posted September 2, 2023 20 green notes for both. I felt like I'd thieved them. 1
Rob Wright Posted September 2, 2023 Author Posted September 2, 2023 (edited) The new transformers are Hammond 500VA 60V. That basically means they can supply 500w of power each. I'm not sure on the specs on the original Perreaux laminated single unit. These new toroidal transformers are more efficient, produce less audible hum and noise and generally offer better sound quality and performance. The four new main caps that will replace the two 10,000uF originals are 16,000uF KEMET, which will offer 32,000uF per channel. The unloaded power may be slightly below the original 300w@8ohm but the reserve and full power, especially into low impedance loads will increase quite a bit. We can measure that once it is finished. He can't measure THD. Edited September 2, 2023 by Rob Wright 3
Rob Wright Posted September 9, 2023 Author Posted September 9, 2023 Mock up of the Transformers and main caps to see where the stuff will fit. All of the MOSFETS have been rematched and reinstalled with new mica past. Caps replaced on the boards. The front feet need to be moved closer together due to the weight of the transfomers. Once it's all mocked up it will have a full rewire done. 1
Rob Wright Posted September 9, 2023 Author Posted September 9, 2023 New auxiliary power supply. It is for the preamp board that includes the Burr Brown and some of the stuff such as the attenuators and the clipping detectors. If this shuts down before the main amp you will get a big pop through the speakers. That won't happen with this setup. This is how all top quality amps do it....probably overkill. 3
Rob Wright Posted September 9, 2023 Author Posted September 9, 2023 (edited) "Power supply was tested and passed. The voltage is essentially the same as it was before despite the slightly lower rating of the Transformer. The previous setup gave just under 85v at idle, this one is 84.4v but when the amps start to run the old system would sag much quicker than this setup so effectively, when actually running, this setup give vastly better performance and less crosstalk." The new Buss bars are hand fabricated. They are for the earth. He has also fabricated a big pin for the dual transformers to sit on. There could be a couple of weeks wait now for parts as something he had on the shelf there was not what he thought it was and there are none in the country currently, so being ordered in. There was an NTC thermistor for the soft starter, a bigger relay and some 10uF caps for the bridges for the main caps. Anyway something for the soft starter is not available and the soft starter needs to be completed first as it fit under one of the right hand side amplifier board. Edited September 9, 2023 by Rob Wright correction 1
Addicted to music Posted September 9, 2023 Posted September 9, 2023 Lott to of soft start products around.
Rob Wright Posted September 9, 2023 Author Posted September 9, 2023 30 minutes ago, Addicted to music said: Lott to of soft start products around. Can you elaborate?
Rob Wright Posted September 10, 2023 Author Posted September 10, 2023 My first look at the Fascia with the Allen key heads in the rack handle holes. I haven't seen it yet as I had it couriered from the powder coater. It's definitely going to need some kind of artwork. Maybe not the original Perreaux stuff as in the very first picture above but ? It's not a 6000B any more. Perreaux emblem and power mosfet. CHANNEL A. CHANNEL B. Any suggestions? 1
Addicted to music Posted September 10, 2023 Posted September 10, 2023 2 hours ago, Rob Wright said: Can you elaborate? https://www.hypex.nl/products/smps-family/softstart-module you can see from the pic it’s a resistor in serious with the mains and then a time constant circuit that operates a relay to bypass the resistors that usually around 10ohms. What you’re looking for here is the size of the traces and whether those resistors are going to survive long term 1
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