Description

See the before pics vs. after.

I had an NOS pair of these amps years ago and have always been sorry that I sold them. I found a beat up pair and have taken nearly 2 years to figure out how I wanted to restore them. Scrapped the rack mounts and face plates, replaced the jacks with gold 5 way posts and gold rca's, original paper caps were replaced with JJ. Amazing sound. I've had AR, Threshold, Sumo, PSE, Dynaco and more in this system and the Grommes are by far the best!

For simplicity, the Trio works fine for my family running little Soliloquys. I had it completely modded by Chris Johnson at Parts Connexion. The pre and cd are now amazing. Chris upgraded the pre-outs for me so I could run external amps. The tuner is nice, has in/out for video too if I want to run the tv through it. Great headphone system also.

The PS Audio helps a lot. Cabling changes all the time from Nordost to Kimber to JPS.
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Components Toggle details

    • Grommes-Precision G101-A
    Mono block tube amps. 6GT5 output tubes, 12at7 gain and 0A2 rectifier. 100/120wpc can drive down to 1.4 ohms continuous. Fast, crisp sound, not "tubey" and bloated sounding at all. I just finished a complete rebuild on these amps, cosmetically and sonically. The tech I took them to for the final biasing thought I was nuts until he got them on his bench. After retubing, biasing, regrounding and a few repairs, the test results were phenomenal. At full volume, 100 watts continuous, they are dead silent, running about 1.8% thd, extremely square wave from 8Hz all the way to 25Khz. He said that the only other tube amps he has ever seen with this kind of test results are $10k Mac amps.
    • Coincident Speaker Tech Conquest
    Coincident Conquest
    • Sota Jewel
    Sota Jewel with Clearaudio Aurum Beta S cartridge and Jelko LMT arm.
    • PS Audio UPC 200
    Line conditioner
    • Nordost Blue Heaven
    Nordost cabling everywhere I can.
    • PSE Studio SLP
    I replaced my Sherbourne Pre and Cambridge 640p with a nice old PSE preamp with built in phono. The quality of PSE equipment is amazing. Simplifying my system helped a lot. Eventually, I will have some minor mods done to this but so far it has impressed me.

Comments 13

Elevick Could you give me the hookup diagrams for these Grommes. I just acquired 3 of them and I want the best way to hook them up to the different speakers I have. I have 4ohm, 8ohm, and 16ohm speakers. Thanks

magnedon

Hello Elevick,

 

  I came across your post reading the SOTA table and wondering whether you can provide the instruction for service the SOTA table to remove the platter and adjust the motor. Please kindly advise. Thanks for your kind assistance.

 

https://forum.audiogon.com/discussions/sota-star-sapphire-help

elevick

2,282 posts

04-02-2009 5:52pm

I've got the instructions to remove the platter and instructions to adjust motor slipping. Email me if you want them-it's not easy. [email protected]

 

Regards,

Will

bbww

I've just found my third unit. So now I have a pair of point to points and an orphan one on a printed card. All are very fine units, I like the cosmetics of the Grommes branded one on the printed card. The pair of point to point ones are badged as Frazier F-105.

I'm now replacing the electrolytics so they will be good to go in a day or two. Is there a speaker hookup that will give me real close to 16 ohms?

I'd like to find a pair of the TL-1a transformers. There is a probable use in my studio as a bridged unit or hooking up 600 ohm mixers.

quayhog

Owner
Quayhog,
I've never seen one with a printed circuit board? Must be a later model. If these aren't matching designs, I wouldn't put much money into restorations yet. If you need schematics on the point to point, just ask. I've got hookup diagrams too.
Advice:
1-The rectifier tube will always flare on start up
2-The 12au7's make a huge difference. Get 4 of the same
3-Tubestore.com has 6GT5's on sale right now for only $15
4-If you can tighten the ground wire on each amp it will make a huge difference getting a proper ground.
Finally, get these professionally biased. These amps will eat output tubes if the bias isn't on. It won't hurt to bias them a little low (90 watts output). This won't soften the sound and really extends tube life.
Enjoy,
Emery

elevick

I've acquired a second Frazier chassis, this one is point to point wired while the other one is on a printed circuit. One day I'll find a cosmetic match. The purchase came with a schematic that is different from the one that is published. It has the key to the output transformer hookups.

I also have a matching pair of S60 amps which use two 6GT5's. I'm going to trace out the circuit. I suspect it's much like the G101a and the front end is like the S35 which is published on the net.

quayhog

Owner
I'll really try to stress that the hookup diagram is a bit crazy and necessary. Any pair of taps will get you 8.4 ohms or the insane wiring for 1.2 or 5.6. The wiring I list above was bench tested and proven to be quite amazing. Email me if you have any issues/questions. emfoods"at"yahoo.com sorry, audiogon won't allow email addresses..

elevick

I did find an orphan pair of Tl-1A transformers. The guy I bought them from gave me a copy of a schematic Id not seen. It has the speaker hookup diagrams for for them. A useful bit information that can aid a lot of amp owners. Im still looking.

I have as S-60 and a similar amp to S-60 which has four iputs and sockets for TL-1A. These 6GT5 amps have me very curious.

quayhog

Owner
Hey Quayhog,
I just saw your question. I've done a bunch of upgrades. The ones that mattered the most were re-grounding the chassis and changing out the taps. Grommes shows that any pair of taps (ie 1&2) will work for 8.4 ohms. However, we found that strapping 4 & 9 and using 3 & 9 for the speaker outputs was far superior.
Also, I replaced the caps with JJ. There weren't any quality 3 leg taps, so I just used 4 leg taps and dropped off one leg. Went higher on all values.
Be careful of which models of 101 you use. There were actually 2 different layouts, one had the inputs on the top right rear, the other on the back right. I think they two are slightly different. You can also look at the Frazier version.
Finally, the TL-1A: I don't think they do anything unless you have a microphone input. I do have them in mine but think it's irrelevant.
Quality 101's sell for $500-600 each while beat up ones sell for about $125 each. Good or bad, I'd buy matching ones unless you plan a massive rebuild. I've had 2 pairs now. I prefer the rebuilt ones to NOS. Both are amazingly clean & fast. Not at all fat, warm or tubey. Email me if you need schematics or help.

elevick

I have one (Grommes brand) and I'm searching high and low for a second.
I'd like to do many of the sonic upgrades after I find the second one.

Did you find it better to bypass the TL-1A transformer? Did you use an alternate? It seems they are usually cannibalized, atleast they were on the auctions I've lost.

quayhog

Owner
Bdp, did you ever rebuild your grommes amps? I just did a ton of work on mine with some astonishing results. Email me if you want some details.

elevick

Elevick -
I've got a pair of the Grommes G-101a's coming in and would like to do the mods you've done to yours. I have the tools (solder iron, etc.) to do the work, but have never worked on an amplifier before - only speakers. Is this something a first timer can do, or should I take them to a tech? Or maybe you can walk me through it, with photos? I would greatly appreciate it.
Thanks!

bdp35

wow. nice job on the Grommes!!!

jsujo

Owner
The first pic, Grommes is the "after" shot.
Pull up the second pic, coincident and it shows the "before" look.

elevick

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