Overview

Wow, that is so weird. I responded to the same thread when Jim offered the discount on the Guttenberg unit. Though, when I look back at my emails with Jim, while I did ask for the Guttenburg unit, he never came right out and said that's the one he was sending me. So it's entirely possible I got something else. I assumed the one I received was the review unit, though. Because, 1) I got the $500 discount and 2) when the Amp arrived, the tubes were already installed and a screw on the back plate was not tightened all the way, as if someone had opened it up, looked inside and didn't tighten all the screws back up. So, it seemed "used" to me. Also the box it came in had been taped closed, reopened and retaped. I guess it doesn't matter. The main reason I mentioned that I had the review unit was just to make sure folks had all the info when making diagnosis/comparisons and offer up one reason why my unit may have some differences. Now you have me even more worried that I have a ticking time bomb in my bias meter!

That's about roughly when I started having trouble with mine, around 300 hours or so. It started with a loud "PoP" shortly after power up, I was in the other room and heard it quite loudly through the speaker(s.) Amp still sounding fine so shrugged it off. A couple days later noticed the meter was only reading 20ma or so and when I tried to re-adjust the bias it would max out at around 55ma? It's a little funny, I've seen you mention before that you had the "review" amplifier- I wonder which one of us actually got that amp as I supposedly bought that amp too. I don't really care if I'm being honest I just jumped after it because of the $500 discount that was offered at the time, which he ended up extending to all new amp sales anyway. Jesse

I wanted to say thank you for taking the time to look at and fix my amplifier- I've had it back in the system for a few days now and it appears to be working perfectly again. As much as I enjoy the 275 amplifier the 285 is head and shoulders better IMO; it has the warmth and tubyness while at the same time solid state like bass and clarity and good high end which by comparison seems pretty rolled off on the 275. Anyway, thank you for stepping up and offering service for this great amp- while frustrating that @Ar9Jim Jim Clark ducked out it is understandable and I don't harbor any hard feelings towards the guy. Jesse

Just a data point for you... I checked my bias meter. It's steady at 75mA at idle and seems to move just fine while playing. I have had my 285 since May of last year. I'm probably putting 4-5 hours per week on it, I'd say. So, close to 300 total hours, i'd say (also this is the unit that Steve Guttenberg used for his review, so, it had some hours on it before I got it).

Thanks @Nahash5150. That's helpful. I've logged a lot of hours on my 285....haven't noticed any issues. I'll check the current bias reading and let y'all know.

The bias should stay between 50mA and 150mA at idle after 10 minutes of warm up. If you've chosen your sweet spot, say 90mA (because that's mine), then it shouldn't change. If it does by more than a few mA, then it could indicate a problem, especially if it won't adjust properly or keeps falling out of your sweet spot. We aren't taking over the warranty. We are just willing to service these units and do our best to support them, unofficially, because right now, there is no official support. I'm sorry I don't know the exact origin of the trouble. I just know that it seems to be related to time, nothing else.

Related question...... is Nelion taking over the warranty work from Jim Clark?... I know he closed up his shop, got a new job and has been real busy. But, on his way out, he did say the warranty's would be honored.

I haven't touched the bias adjustment on mine. I was advised I may never need to do so. How would I know if I have an issue?

Greg, I haven’t had this problem yet. Is there maybe a certain amount of hours before it appears? Or is a bad transformer?

For those experiencing issues with the bias setting on the RAM285, the issue is likely with the burn-in effect of the circuit and transformer winding that powers the bias circuit. Many Bob Carver Corp amplifiers experience this trouble. Common complaints are: - The bias does not adjust high enough. - The bias does not adjust low enough. - The meter is not working. Unfortunately, there is no DIY fix for this. The RAM285 has extremely unfriendly serviceability. The PCB hides most components and is multilayered. Reworking the circuit board requires technical experience and proper tools. Moreover, the trouble has common causes but it may also be related to other less common troubles, so the amplifier should be fully tested to verify what the real trouble is. Please inquire with us to get your RAM285 serviced if it is experiencing any trouble.

I used Krud Kutter - The Must for Rust solution

Nice work, Greg. Can you share what you do to "de-rust"..., do you use mechanical or chemical derust techniques? My mother just gave me the old Fisher amp that I grew up with..., and she had it in her basement. My first look at it, and I realized the basement humidity had done a similar light rusting to your hafler...

Very nice - that amp was pretty crusty.

A received a Hafler DH-220 to fix along with an extensive upgrade kit. It came with a USB drive with docs and pics. A well put together project. The unit was in dire need of service. Old, crusty, and very dirty. Top of unit: Near power switch and primary fuse: Taken apart: I removed most of the screws and derusted them, then cleaned and derusted the chassis, heat sinks and other various parts. It was a load of work! But it cleaned up pretty good. All new amp driver boards that had to be stuffed by hand. Crazy! New speaker binding posts and RCA jacks as well. It looks so much better now though: Sorry - forgot to snap a picture of it all put together. But here's an internet one:

Really sweet. The gold-plated ground screw is a very nice touch.

Do you ship to China? 😁

We can do that... C-4000 C-1

Problem: Main reservoir capacitors venting Solution: Full restoration! The main reservoir capacitors on the 5ch and 7ch models have reached their end of their usable life. They will boil, and vent - possibly causing permanent damage to surrounding circuit boards. Electrolytic fluids are corrosive. Furthermore, if these large main capacitors fail, they can damage the power supply by shorting to ground on one side, in a normally balanced supply. In most cases, the main fuse will blow from the failing capacitor, but there is no guarantee.

Problem: Severe burning of the PCB around regulator circuits on dual channel boards that can lead to permanent damage Solution: Full restoration! The regulator circuits need to be rebuilt and modified to prevent future burning. Without service, these amps can be become UNUSUABLE.

Makes one concerned about shipping when buying one of these, and it's going to be packed and shipped by someone that ..., has no idea.

Make sure the power transformer is as secure as possible. Tighten the 4 large screws on the bottom of the chassis until they are snug. If the transformer still feels loose, pop the top and tape some cardboard over the transformer top, just enough to fit under the metal cover. Or this can happen:

I have had two clients inquire in just the past week reporting that their (unserviced) Sunfire amp has blown the magic smoke and needs repair. This is becoming more common. Please get the word out that Sunfires need to be serviced. If they blow smoke/catch fire the service becomes more expensive - if it's even repairable. Last year, someone sent me a burned up unrepairable TGA-5400. Gorgeous, rare amplifier...gone. So I think it's time for a reality check. Many Sunfires are too old to gamble with. They have substantial power and self-destruct rather violently - more so than I think people expect. Also, be wary of local repair shops. Sunfires are not easy to work on (even we have to use specialized equipment) and most techs out there do not understand how they work. So it's also common for us to get Sunfires that were not repaired correctly from local shops.

Sold! I was going to refresh my C-1 myself and do the Bill D mod. After hearing this, I'm going to hold off on doing any of the C-1 work myself and send it to you guys. But I'll wait a few weeks after I get my M-1.0t back from your shop. I want to enjoy that for a bit.

First, the hardware is integrated with the C-1, so there's no external box. Second, this hardware is not just bluetooth, but also connects to your wi-fi so you can stream via Spotify, Apple Music, etc. And it will stream music from a NAS or PC that uses the DLNA protocol. Many home routers have a USB input, so you could connect an external USB harddrive full of music to your router USB, and this hardware will stream music from that as well. This is all done though the phone app that connects to the hardware.

Intriguing idea! I'm especially interested in direct streaming to my C-1. Without giving away any secrets, how would it differ from something like this (I currently use one): https://www.amazon.com/dp/B016NUTG5K?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_20 Lastly, in your minds eye, when do you see this available to the general public? Definitely a cool idea!