View Full Version : GROMMES 260 modified valves audio amplifier

alex mm
07-28-2010, 07:27 PM
Hi all ,
Tubes preamplifier ,without final stage it's not posible ,to hear music at right level ,so I present somes pictures of my tubes amplifier :D :D :D 243244245246247
Regards Alex.

alex mm
07-29-2010, 04:38 AM
.....over the night was aseambled .......pice by pice ? :) More pictures below

alex mm
07-29-2010, 04:42 AM
bottom side 253254

12-06-2011, 08:43 AM
Hello Alex,
Nice build. I am looking to build Grommes 260A Tube amp, This is first time I will be working on Tubes, so can you you guide me.

Thank You

alex mm
12-11-2011, 09:11 PM
I enjoy every day , my amplifier sound very good , linked of course with my tube preamplifier , so I decided to repeat experience at large scale with biger output tubes , this time I will use military russian GU50 vaccum tubes.
Used schematic stil the same Gromes 260A . It missing as usual the box (case) wich will be something nice ......
Regards Alex.

alex mm
05-07-2012, 10:28 AM
....... I finished my second Grommes 260A modified with succes ,sound clear , dinamic , soft , tube sound I like very much :UP: . Some pictures attached......
Regards Alex.

alex mm
05-23-2012, 08:35 AM
....... it seems no one like tubes amplifiers , to hear this amplifier you can access this link http://www.youtube.com/watch?v=wIqaRohcJwI .
Regards Alex.

05-25-2012, 05:58 AM
Hi Alex, that looks really good, it's a good amp :cool: The GU50's look strange with metal ring on the top, what is it for? How much is B+? Where did you get the transformers from. I use Hammond (http://www.hammondmfg.com/claspg.htm), Jensen (http://www.jensen-transformers.com/), Sowter (http://www.sowter.co.uk/index.php) transformers.

My amp is 6550/6SN7/12AX7 I built in 1984 and it sounds incredible. Worth all the sweat and $$$ for transformers. Magical at times...
For a pre-amp, I made a Pultec clone (http://gyraf.dk/gy_pd/pultec/pultec.htm) without the EQ section. Highly recommended, for headphones too.

alex mm
05-26-2012, 03:49 PM
Hi Redwire ,
Thanks for the kind words , GU 50 are military RF tubes and for this reason are built with metal ring on top and more glass as usual . My B+ is only + 426 Vcc , and output transformers are made by LMO a specialist . Unfourtunately I can't buy from ....... All tubes amps sound incredible , are magic , and you did also an great job . I wish you succes , all the best ....... A tube , is a tube ......
Regards Alex.