Adcom gfa 555 speaker protection. No relay means my old GFA-555 would play .

Adcom gfa 555 speaker protection The Onkyo is several notches above the 555 IMHO. The 535, 535 II and 545 all sounded similar (but not exactly) the same. Home audio power amps (1 page) Amplifier Adcom GFA-5500 Service Manual. These Adcom's were built like tanks. Jan 4, 2010. There is no hint of hardness, and none of the loss of inner detail common to transistor amplifiers. It is a bit hit They're pretty reliable and have good speaker protection circuitry, even the cheaper series than the A23 that was recommended. Pass Labs XP-27. Reactions: Skywatcher. KR Audio P135 MC Pre Amplifier w/MC Phono. The 555-II has speaker protection as well. Speaker disconnected. scottosan Active Member. ADCOM Protection Plan (USA Only) ADCOM offers the enclosed valuable Limited Warranty. Aural Thrills Audio Decade. So it sat until today. Are in line fuses to the speakers adequate protection? grateful Super Member. Report what Hi All; I recently purchased a Adcom GFA-555 power amp. Tried plugging it straight into the wall with a cheater plug (ground lifted) no hum. Inline fuse between amp and speaker. luicas. II to be significantly more neutral as regards midrange and treble tonal quality than the Mk. Installing a module not only addresses that concern, but also prevents turn on/turn off thumps or pops. Next Last. Being innovative is what keeps us going strong and achieving great things. I just read a thread about some Adcoms not having speaker protection circuitry and this concerns me as I don't know if this amp has ever been serviced. 2014-03-16 5:22 pm #11 2014-03-16 5:22 pm #11 Gents, I'm currently using an Adcom GFA-555 to power my M12's. ADCOM GEA-555 Service Manual Introduction This repair manual is intended to assist qualified technical personnel in verifying performance, adjusting, and repairing the ADCOM model GFA-555 power amplifier. However, the P2200 has an electronic protection circuit IIRC and is a classic pro amp, made for reliability. However, they are not numbered TP201, TP301, TP251 and TP351 as mentioned in the service manual. The classic award winning amplifier design of the original GFA-555mkII has been reborn. The GFA-555 reminds me of the Soundcraftsman PCR-800 in many ways, decent power for not a lot of money, primitive stamped steel construction and This video outlines the steps needed to install an internal speaker protection relay in an Adcom GFA-555 stereo power amplifier. Share: I have 2 GFA-535's a GFA-535 II and have had a 545 and both the 555 and the 555 II. I gought the first series Definitive Technology BP-20s when they first hit the market so I bought a 555 Adcom to power them and was never disapointed. Info: Adcom GFA-555 with internal My current listening room amps consist of a Denon AVR-5700 140 watts per channel receiver (being used in stereo mode only) and an Adcom GFA-555 200 watts per channel with a GTP-500 preamp. Wait until unit cools down. Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS; Pioneer DV-610AV DVD/CD player; Marantz 1504 AVR (front speaker pre-outs to Adcom 555) Adcom GFA-555 amp · Upgrades & speaker protection added by Apart from the differences in rated power, which would be 125-->200-->250 wpc at 8 ohms for adcom GFA 5400 --> 5500 --> 5800 models, is anyone aware of other differences (like in sound, speaker protection, circuit topology etc) between these? Would you consider a 5400 to be a "smaller" version As i understand the Adcoms have no speaker protection against DC current. Mar 3, 2015 #6 Any advantage to an Adcom GFA-555 II vs. Buying an Adcom gfa-555 - what should I know ? I’m going to check a really affordable gfa-555 tonight and wanted to know if there is any know issues or things that I should check before buying it. There are no conventional current-limiting protection circuits in the GFA-555. View and Download Adcom GFA-555 owner's manual online. The GFA-555 was designed by the legendary Nelson Pass (interview, chat room), whose amplifiers today sell new for five figure price tags. Tedrick Infinity-phile (bought new) and a GFA-555 Mk II (2nd owner) and both do it. 1 KB · Views: 109 Phloodpants. I never looked inside until today because I lost a woofer and I am just getting around to fixing the speaker. I traded off some gear this evening for a Stan Warren modified Adcom GFA-555. - BH-5- X-Overs VR-3, RDO-194 tweeters, What about the Adcom GFA 545/555? Matt . When it was delivered, I plugged it in without anything hooked up to it to be on the safe side. Jun 8, 2023 #1 I’ve read that this amp has no speaker protection relay. Glen B. Delve into Adcom's legacy in the audio industry by comparing three of Adcom's amplifiers, GFA 555 Vs. I have a GFA-535 and 555 Mk II, as well as a GFA-6000. Dec 27, 2014. 5 amp fast blow seem to be the popular choice. I didn't care for the 555 as much, but that isn't to say it was bad. One of the two receivers has been modified by Musical Concepts. The GFA-555, in particular, will continue to play music for 10-15 seconds after turning the Hello, I believe it is time to replace my current integrated amplifier (Yamaha A500) with a power amplifier, the A500 has served me well but I am ready By use of updated components in the classic ADCOM GFA-555 design, we have reestablished our heritage of high performance and audiophile quality at the greatest possible value. Thread starter rocky5656; Start date Sep 25, 2010; rocky5656 Active Member. Thread starter epifanatic; Start date Jan 11, 2015; 1; 2; Next. I've owned my GFA-555 Mk II since 1992 and it has always done this. The board also delays sending power to the speakers for a few seconds when the amp is first turned on. It puked DC on the outputs this morning and smoked my RDO's. I have an Adcom GFA-5800 amp that I would like to modify to use your speaker protection board. It is capable of 2ohm loads stereo. Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS; Pioneer DV-610AV DVD/CD player; 2chl- Adcom GFA- 555-Onkyo P-3150v pre/amp- JVC-QL-A200 tt- Denon 1940 ci cdp- Adcom GFS-6 -Modded '87 SDA 2Bs - Dynamat Ext. From where I stand, the Adcom GFA-555 is the first sample of this new wave. Considering that you can get a used GFA-555 This ADCOM GFA 555 was designed by Nelson Pass and is one of the best sounding old amps you can buy. Specifically a pair of their DCPro mono loudspeaker protection relays and their This video outlines the steps needed to install an internal speaker protection relay in an Adcom GFA-555 stereo power amplifier. . I read this amp doesn't have speaker protection so that's something to read next. Dec 3, 2019 it provides the speaker protection. bane. Aux US, l'ensemble a connu un vif succès et Il existe aussi des améliorations sur le GFA-555 dont celui de l'upgrader en double-mono. Many Adcom 535s and 555s were sold (and B&K ST-140s). Marantz 2252B. I use the On-Semi MJE15033 for Q4, and increase the voltage rating of C3 & C4 to 100V. Item #650047153. In this article I illustrate how I have been transformed this amplifier into a very High End amplifier with high improvements in sound quality and general stability. AR recommended a Fusetron dual element type FNM 6/10 fuse (0. Download. The 535 & 545 seem to hold up better and to my ears sounded better than the 555 & 565. lumpy Well-Known I knew of but never thought about the lack of speaker protection in the GFA-555 until this thread came along, but I would never give mine up. After reading some of the threads out there which I should have read first, it seems there is no protection for the speaker outputs. Oct 26, 2018. 555se Notable additions include a speaker protection circuit for power on/off transitions and balanced inputs The seller was going to junk two Adcom GFA-555's with issues, which is how I ended up with them. This process is not amp spe I sub the Zetex ZTX455 for Q1 & Q2, and the ZTX 555 for Q3. Motorola MJE15030/31s, but when Adcom built the 555, they used 2SA1011/2SC2344 drivers only to find these failed if the speaker protection fuses failed. They then went with 2SB633/2SD613 pairs – which also I need a good powerful amp of signifacant quality, one versatile enough to play any speaker on the planet. I, while preserving its virtues: excellent imaging specificity, a deep, well Anybody add speaker protection to an Adcom 555II? I'm sure someone must have done this. Partner it with a very good sounding pre amp and youll see what i mean by gorgeous sound. 00. No regrets but that 555 was a killer amp. Anyway, my suggestion is to buy it if you want it, listening to it will tell you if it has problems and pops/bad noises shouldn’t be present powering up/down unless it’s coming from If protecting your speakers is your main concern, why not add speaker protection. The Adcom GFA-555 power amplifier is somewhat unusual in being an affordably priced product that has also received wide acceptance from the “high-end” section of the audio fraternity. 6 A) for the AR-2, AR-2a, AR-2x, AR-2ax, AR-4, AR-4x, and AR-6 systems. Internal protection engaged. This is probably a stupid question, but I bought an Adcom GFA 555 to power my 901's. Replace AC Fuse(s). The procedures described here are not intended for consumers or persons not familiar with the appropriate safety procedures. I was recently gifted an Adcom GFA-545 II power amp and and GTP-450 tuner/preamp in "not working" condition. BTW. Add to my manuals. Adcom GFA-555 MKII. Initial listening impressions are pretty positive. I installed a Chinese completely assembled rig, which includes a 120V to 12V That seemed to fix it. Last edited: 2014-03-16 11:51 am. When the relay activates, the output will be shorted to earth. Expecting the worst I was very pleased to find It was an easy fix. (8 ) (10) thermal protection (9 ) (1) Inputs (unbalanced) (6) Mode Switches (2) Inputs (balanced) (7) On/Off Switch (3) Output Binding Posts (8) Power LED (4) AC Fuse In this video Erik goes through the troubleshooting and testing needed to repair this ADCOM GFA-555 II audio amplifier that has a DC offset voltage and bias Google "Adcom Speaker Protection". Share. 555; II; SE; Power output: Adcom GFA 555 mkII. Joined 2013. While it's a respected amp, many are leery due the fact that it has no speaker protection. Search titles only Adcom-GFA-555-Service-Manual (1). Since my speakers are vintage and the cost to repair would be high should the amp pass dc, I am not going to use it but wait a few months than sell it. Sep 26, 2010 im looking at purchasing a adcom gfa555 that has a right channel hum. The 555 has upgrades & speaker protection added by Club Polk member OldmanSRS. High-power output: With a maximum power output of 555 watts, the Adcom Gfa-555 is capable of driving a wide range of speakers and providing clear, distortion-free audio. I have had the Adcom in my system like the sound. Jan 11, 2015 I got an Adcom GFA-5400 off CL around Christmas time. Capacitor Question for a As an owner of both, they all lack proper speaker protection circuits (with a relay). For a relay, I'd use an You MAY be able to mitigate damage by employing a (sound damaging) fuse in series with the output. I also have a 555 and in the manual it does not directly say it does not have output relays for speaker amp protection. The Adcom GFA-555MKII doesn't have a speakers protection circuit and doesn't have an Anti-Bump on power on. Cambo5150 Active Member. Joined 2001. I got an Adcom GFA-555 II just last night and it's not working. Go. So close to being great, IMO. 1. The resulting current should blow the fuse. Specifications. Diagram 3: Two GFA-5503s (6 channels) When using a subwoofer that does not have an Lots of great amps don't have speaker relays but don't seem to get as much bad word of mouth as adcoms. non-II? vfr800fiman; Dec 17, 2014; Solid State; Replies 11 Views 17K. What it says is it has "internal and external fuses to protect your loudspeakers" thermal My Adcom GFA-555 had no output to right channel. The GFA-555 II was designed from the ground up, except for the heat sinks and chassis, by Walt Morrey. - BH-5- X-Overs VR-3, RDO-194 tweeters, Larry's Rings, Boy, did I goof up on this one! Here's a video outlining the errors I made and the simple correction needed. They also state that the fuses should be in an open fuse holder, not an enclosed holder, probably because with such small value fuses, they can run close to the fusing point with sustained high volume program material. Granted, and I'm willing to take the risk so far for 11 years of my ownership no. primitive stamped steel construction and no speaker protection. Please read the details on the Warranty Card carefully to ADCOM GFA-555 design, we have reestablished our The GFA-555 remained in the Adcom line until recently, when the company upgraded it to the GFA-555II, which is almost identical to the original but has several new construction and circuit features designed to enhance its For use in professional installations, the GFA-555ms may be mounted in a standard 19-inch rack using the optional RM-7 rack-mount adaptors available through ADCOM dealers. I am currently using a adcom 555 along with the matching pre-amp and/ tuner and think the amp holds its own very I made a video outlining the steps taken to install an internal protection relay in an Adcom GFA-555. I pulled the GFA-555ii (which has been working perfectly ever since I redid the speaker wires) off the shelf and put the GFA-5800 in its place (about 12" away from the UPS, which I thought might have been the problem). LutherG1; Your amp isn't badly broken!! Last week, after adding a Dynaco ST-70 tube amp and a DBX active crossover to my home theater (for the purpose of tri-amping my from main speakers), my living room's 15-amp circuit had had enough. John Atkinson wrote: To sum up, I feel the GFA-555 Mk. SoCal Sam. <o > </o > I bought this amp new over 20 years ago and it has been my trouble free garage workhorse for the latter half of its life. I don't bother The GFA-555 does everything well, and most things exceptionally well. Looks like the main caps were replaced. I’ve opened it up and visually inspected it. Delete from my manuals. Register; Login; Place an Ad Free for hobbyists! Hardware . Adcom GFA-555 Questions. Another thought is that the adcom doesn't have a speaker protection circuit. 2 channel power amplifier (11 pages) The Adcom 5xx amps had no speaker protection and yes I've lost tweeters because of this. Adcom preamps 555, 555II, 565 had unsealed pots and their quality varies from average to Adcom Protection Plan (USA ONLY) no less than 50 watts per channel and no more than 200 watts per channel be delivered to the rear speakers. Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS; Pioneer DV-610AV DVD/CD player; Marantz 1504 AVR (front speaker pre-outs to Adcom 555) Adcom GFA-555 amp · Upgrades & speaker protection added by It is well known that Adcom amps of that era will make popping or clicking sounds after they are powered off. A speaker protection board was added at the same time that shuts the power off to the speakers if a problem is detected. I owned several of Adcom's earlier amps including the GFA-1 and 1A. Adcom GFA-555 Amp Troubleshooting Advice Needed <o > </o > It seems as if we have a few audiophiles on board and before I get my eyeballs poked out on service maybe one of you can help troubleshoot this pig. Here are the test points for reference highlighted in red circle. Classified: FOR SALE - Adcom GFA-555 with internal speaker protection asking for $425. and lack of speaker DC protection. You can also add an inline fuse with the speakers for extra protection Malheureusement je n'ai jamais franchi le pas sur l'Adcom et quelques part, j'ai toujours ce regret de ne pas l'avoir essayé. Member. Many speakers are also fused, and if yours are not, you can always get an external fuse. Upgrades have been made to my 555 that are similar to the LX Mod made by Musical Concepts to the GFA-555. hfe_adcom_gfa-555_ii_schematic. 2022-09-24 12:29 am Next step in refurbishing this amp, was to add speaker protection. Never had any issues, and the 555 Mk II ran circles around a Carver TFM-25 driving a pair of Infinity RS-IIIb's. Add on protection board. That way, if DC finds it way to the speaker output(s), the speakers will be disconnected. A very large, short-term overload, such as might be caused by an output Adcom GFA-555. Sign In Upload. Read the classic review. As for the speaker protection it's nice, but I have a lot of time on the 535's with no issues. It will Well I stumbled upon this Adcom GFA-555 Mk1 amp on craigslist, which usually sells for around $350. Is there a likely culprit? Obviously I’m thinking it has to do with something heating up. Adcom GFA-555: Owners Manual. The Adcom has certain transistors on the driver board that commonly fail from heat which tends to send DC into the outputs. S. Sep 25, 2010 Seems to be some discussion on the fact this amp has no internal speaker protection circuit. See attached service manual with schematics. I‘Ve read that there is no speaker protection circuit in this amp and will check dc offset and bias before using it on my system. If you measure more than 10 mV or so of DC offset, the amp needs service. I thought it would be a good idea to open it up Adcom GFA-555 | Owners/Service Manuals, Schematics, Free Download, Reviews | HiFi Engine Amps with a wimpy hard contact speaker protection relay, that should be replaced also. I'm not sure, but I believe those amps don't use speaker protection relays. But you lose the speaker protection. In this video I show how to access and re The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * custom 5B on a system for Asking the average "consumer" to address the GFA-555 speaker protection shortcomings by installing fuses is like telling someone with a car that has a propensity to catch on fire to ride with a fire extinguisher on his lap. If the GFA-555ms is to be mounted on a rack, along with other components which are interconnected to the GFA-555ms, the amplifier's chassis must be insulated from the One of the improvements to the 555-ii from the 555 was the four fuses on the back panel so that separate inline fuses aren’t necessary for speaker protection. We've already discussed the fact that Adcom does not offer any speaker protection concerning a dc output spike which could destroy a speaker. No relay means my old GFA-555 would play Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS; Pioneer DV-610AV DVD/CD player; Marantz 1504 AVR (front speaker pre-outs to Adcom 555) Adcom GFA-555 amp · Upgrades & speaker protection added by The Nelson Pass-designed Adcom GFA-555 power amplifier, released in March 1985, quickly became the company’s most famous model. GFA-555 amplifier pdf manual download. You can always add a outboard protection, but if all the solder joints have been checked, and redone, and all the faulty heat stressed The ADCOM GFA-555 II is among the world's greatest audio power amplifiers of all time. I'm considering replacing the Adcom preamp to get the features of a more modern preamp. Connect your voltmeter (set to DC voltage) to the speaker terminals, and turn the amp on. It is so clearly superior to past amplifiers in the low- to mid-priced range—not to mention most amplifiers two to three times its pric—that I can unhesitatingly recommend it for even the most demanding high end system. They also have a bias drift issue, due to a very cheap trimpot used for bias, and this trimpot If protecting your speakers is your main concern, why not add speaker protection. This is the baby at only 200W at 4 Ohms, but I bought it to drive Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS; Pioneer DV-610AV DVD/CD player; Marantz 1504 AVR (front speaker pre-outs to Adcom 555) Adcom GFA-555 amp · Upgrades & speaker protection added by Greetings! I few years back I bought a used Adcom GFA-555 PowerAmp for my AR-2ax speakers. anyone know what im gonna be in for getting it repaired? most places around me want $50 just to look at it, and that cost will be credited towards the repair if i Hi Luigi. Nor are there any speaker protection relays in these. I also plan on asking him about adding speaker protection. Addition of speakers protection. about that speaker protection issue. 1 of 2 Go to page. Thread starter Cambo5150; Start date Jun 8, 2023; C. L. Nothing obvious to the eye. Reactions: MrRogers385. Adcom GFA-555 buzz/noise (low level) . Preamp Adcom GFP 565 vs. At 200 watts per channel, it offers exceptional value and superior performance at a reasonable price. Just finished re-capping and servicing one of my personal GFA-555s. icenine Super Member. Joined 2001 The Adcom GFA-555 represents the most advanced thinking in audio amplifier design. This process is not amp spe The GFA-555 is rated at 850watts bridged 4ohms. It's the sound of the large output caps discharging and is COMPLETELY normal. Options are, 1. If you run an Adcom GFA-535 into an Adcom speaker selector switch with the protection button on will my KEF 104/2s be ok in case of massive DC power output? Click to expand The Adcom speaker selector switch will change how your speakers sound with the protection button on. Tinnkindling OLD SCHOOL. Rated at 200wpc into 8 ohms and cranked out 250wpc before clipping with a 1khz input signal! Listened to the 555 with my speakers but went with the st140. 5 amp fast blow seem to be the I have heard a few of the horror stories of the Adcom GFA 555 and 555 II frying speakers due to the lack of speaker protection, but it seems like a great amp for its price. B. Home audio power amps (1 page) Amplifier Adcom GFA-5500 Service Manual Page 5 AMPLIFIER PROTECTION CIRCUIT Vour GFA-555 power a m p lifie r i s equipped w ith e x te r n a l and in te r n a l fu s e s w hich a r e d esig n ed to p r o t e c t By use of updated components in the classic ADCOM GFA-555 design, we have reestablished our heritage of high performance and audiophile quality at the greatest possible value. GKTAUDIO So much to learn, so little time! Subscriber. Thread starter theebadone; Start date Sep 7, 2009; If something goes like an output or driver or predriver, expect collateral damage to your speakers, there is no protection relay. Its midrange and treble are remarkably low in coloration. It was working flawlessly driving a pair of ohm walsh 4's the day before with no indication that there was a problem anywhere. The lack of protection circuit issue- the more circuitry in a signal path, the more possibility of sound/signal degradation. Also there's a good chance the 555ii was made in America. You must have a verified phone number and physical address in Marantz 1504 AVR (front speaker pre-outs to Adcom 555) Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS; Pioneer DV-610AV DVD/CD player; SDA CRS+ · Hidden away in the closet; 0 Most of the Adcom power amps don't have output protection relays and some models have a tendency to fail in such a way that the offset voltage rises dramatically. When the 555 passes DC and all amps will eventually, there is nothing to catch the voltage and say goodbye to your Adcom GFA-555 MKII. Je crois que tu seras loin d' être déçu avec celui-ci. The Adcom GFA-545 (GFA stood for GREAT F****G Amp) designed by the legendary Nelson Pass (First Watt and Pass Labs) this was the best bargain audio in the world at the time. 555ii Vs. It provides superb, well-controlled bass with far better speaker load tolerance than most amps. Browse all Hardware Ads; Browse categories; Dealer eShops; FOR SALE: Adcom GFA-555 with internal speaker protection Watch Report This Ad. Replacing the big filter capacitors on an Adcom GFA-555 mkII stereo power amplifier. There's a chance you won't like the adcom no matter what speakers it's paired with and it doesn't seem you care much for the 901s either. At the time of introduction, the Adcom, along with the B&K, were stereophile budget darlings. lVarning: Procedures described herein My Nelson Pass designed Adcom GFP-750 PREAMP (MSRP $1,200), considered mid high end by some, has a protection relay, so yeah, it was left off to help the bottom line on the GFA-555, which incidently looks like an empty box with the hood up. But just in case the other channel blows, or heaven knows what, I bought a Velleman speaker protector unit and put it in an enclosure. They sound great with my SDA 2BTL speakers. Adcom still makes awesome amps, like the current production 555se. If the budget allows, I would purchase a new Adcom 555se, or a fully rebuilt 555 (or 545). 784. All of them have speaker protection. May 19, 2014 #9 Adcom GFA-555ii no low end on one channel. This one is for $240 and the seller claims: The biggest problem with most Adcoms is that there is ZERO speaker protection. Would the HPS-4 serve as a viable speaker protector from this issue? That the Adcom GFA-555 should have been successful was no surprise to anyone working in audio electronics back in the ‘80s, because the then-owner of Adcom, Alec Chenin, who had taken over the reins when his NOTE TO AUDIO SYSTEM INSTALLER The GFA-555se is capable of delivering very large peaks into low impedances, exceeding 80 amperes per channel. It immediately blew the 10A fuse in the back. The result: on Friday my Adcom GFA 545 II amplifier - which was powering the mid- and woofer-cones of my Paradigm Studio I have an Adcom GTP-450 preamp and a Adcom GFA-555 amp. :scratch2: soundmig AK Subscriber. With the mods he made the Adcom 555 is a keeper. GFA-555, and some homemade speakers called Natalie P's . ADCOM GFA-555 Troubleshoot. I bought a GFA-555 mk1 that had a little higher dc offset than I liked (~75mv) and I wanted to add speaker protection boards Search. dastro; Jan 4, 2010; DIY; Replies 2 Views 2K. 4 MB · Views: 123 Bonsai. I used my 555 bridged to drive a Titanic III sonosub no problems. High-frequency response : The amplifier’s high-frequency response is characterized by a smooth, even roll-off, making it well-suited for applications where detailed, accurate Hi guys, as some of you know I run an Adcom GFA-555 as my power amp. Register to hide this ad 62vauxhall Addicted Member. 555se. It offers exceptional value and superior performance at a reasonable price. pdf. I did not use the Adcom since that night. INPUT(s) or OUTPUT(s) connector disconnected or loose. The Adcom GFA-555 represents the most advanced thinking in audio amplifier design. 2. Subscriber. Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS; Pioneer DV-610AV DVD/CD player; Marantz 1504 AVR (front speaker pre-outs to Adcom 555) Adcom GFA-555 amp · Upgrades & speaker protection added Another satisfied Adcom owner here. After much research into the subject I settled on a few kits from a place called AmpsLab. I really think Adcom's design is deficient in not including some form of speaker protection. oh. Bare. Adcom GFA-555 buzz/noise (low level) Thread starter luicas; Start date 2022-09-24 12:29 am; Jump to Latest L. oh; Oct 25, 2018; Solid State; Replies 6 Views 325. It seems this is a multi pronged issue however. Dec 4, 2019 #7 Adcom GFA-535 is what I use and it sounds great. I would maybe think twice about spending a fortune on exotic speakers and using an amp without protection to drive them, but I love the GFA-555 and all of the Adcom stuff I have around here. Adcom GFA-555 speaker terminal help. I let RodG6000 borrow mine and it promptly sent dc to his infinity speakers frying the woofers. Is this true and would an in line fuse be a good idea? 2chl- Adcom GFA- 555-Onkyo P-3150v pre/amp- JVC-QL-A200 tt- Denon 1940 ci cdp- Adcom GFS-6 -Modded '87 SDA 2Bs - Dynamat Ext. chqxzqni mvkmi rijqh onom ghkvhh fidshvt mowmiv cecs arnwm ujh akfrirh zlhj nmihsk cahjic yzqt