Mostrando entradas con la etiqueta valvulas. Mostrar todas las entradas
Mostrando entradas con la etiqueta valvulas. Mostrar todas las entradas

20 de noviembre de 2008

Posiciones de tubos y sugerencias para el C30

Tubos del Pre-Amp:
Posición V1: Canal Limpio -Tung-Sol o Mullard 12AX7 Re-Issue
Posición V2: Distorsión -JJ ECC83S High gain
Posición V3: Inversor de Fase -Sovtek 12AX7LPS

Tubos Etapa de poder: Mullard or JJ EL84's Matched Quad Set

Rz

28 de septiembre de 2008

dealers de tubos en santiago

aquí pueden revisar precios ... en dealers en Santiago ...
yo le he comprado a Mex, super buena onda; yo me equivoque de modelo, y el amablemente no tuvo ningún inconveniente en cambiármelo.

http://www.mex.cl/power.htm

http://www.importedgoods.cl/ehxtubos.html


Rz

EL84 Tube Type Review

The Complete Reviews

Electro Harmonix EL84-EH - For most applications this is a good bet. The sound of these tubes is very smooth when biased correctly. Tonally, it’s hard to go wrong. They are pleasant to listen to and have the creamy overdrive most people look for in an EL84. They have a nice chime but it’s not overbearing. It looks a lot like the standard Sovtek but a closer inspection will reveal differences. The plate looks a bit more polished with a different coating and internally they feature precisely wrapped grid wires with a bright metal shine. The only problem with this tube is that like the Sovtek and TAD product, they are tubby. The fattest one I measured was .886 inches thick against the G.E. maximum width spec of .875 inches. For most purchasers this will not be an issue. If you have an amp that requires the tube to pass through a hole in the chassis before the pins seat in the socket you should measure the diameter of that hole. If you’re still unsure, the JJ EL84 is the closest in dimensional specs to NOS measurements and the G.E. standards for the 6BQ5.

EL84 (also 6BQ5) - Power Vacuum Tube

Sovtek EL84 - The Sovtek EL84 has been a staple for Fender, Boogie, Crate, Peavey and other manufacturers of tube amps using the ’84. This tube really is a good value. It is predictable, reliable and affordable. You can get good EL84 tone at a reasonable price. The Sovtek EL84 has been around a long time, and it has shown continuous improvement over the years. Using a matched set of properly biased tubes will yield a clear smooth sound that is fairly warm and transitions into a smooth breakup with that singing tone that EL84’s are known for. In cathode biased amps like the VOX they get a premium workout and will suffer some effects from heating and cooling. Being prone to mechanical noise in a combo amp, the EL84 is not recommended for amps with poor air circulation. The heating/cooling cycle inside an AC30 easy-bake oven seems to loosen up the mechanical structures within the tube causing them to become very noisy (mechanically) with time. This is true of any amp that uses an EL84 in a poorly ventilated chassis/cabinet arrangement, so if this is your rig, go for the JJ or Russian EL84M.In the Fender Blues Junior the tubes can really put out respectable volume and great tone for all types of music. The highs are not harsh, the mids are warm and the bottom end is not lacking. If you want to really scream try a Pro Junior with full volume. Very crunchy yet smooth with great singing sustain. I personally like my tubes biased at 60% or 70% of static dissipation and the Sovtek EL84 performed well in this range.

Russian EL84M - Some people will swear that the “M” stands for military but I’m not convinced. They look pretty much the same on the outside as normal Sovtek ‘84’s but there has to be something extra happening. The M’s seem less prone to mechanical noise and will do much better at surviving the VOX torture test. I loaded up the AC30 with a quad of EL84M’s and found that they could be run for a couple of hours without overheating. The Heat/Cool cycle still has some affect on life but the 84M lasted longer in this environment than the standard fare. A good choice if you have a cathode biased amp or like your tubes biased to more than 70% of idle dissipation.You do pay a sonic and financial price for the EL84M. They are more expensive than the standard EL84 but will last longer. Sonically they are a bit of a different animal. People refer to them as sounding stiffer or more strident with more headroom and may not like the breakup characteristics when pushed. It is really a personal judgement call. If standard EL84’s have been a problem due to heat or noise and you find they don’t last as long as you would like, try the EL84M and see what you think of the tone. In my opinion they are worth the extra money for reliability and the tone is still classic EL84.

TAD EL84-STR - The STR designation tells us that this was a Special Tube Request by the Tube Amp Doctor. In all honesty it looks and sounds like a pretty radical take on the EL84. The dimensions of this tube deserve your attention. Most tubes made in the U.S., England and Germany were built to a standard size. I often compare the new breed of EL84’s to the 1964 G.E. Essential Tube Characteristics Handbook. The TAD EL84STR is about a quarter inch shorter than any EL84 on the market and falls below the minimum GE spec of 2.344 inches. You may have to modify or adjust spring and clip type retainers for the shorter bottle. These are beefy bottles as well, with a measured maximum width of .874 inches. The GE specification is a maximum value of.875 inches. The TAD EL84STR also has the largest plate structure of any EL84 you can buy. I won’t give any more specs. Just trust me on this one, it’s enormous! There is very little clearance between the plate and the bottle and they get hot! This tube has the deepest bass, the highest highs and strident mids. In short, they sound a lot like a premium 6V6. No smooth creamy distortion here but tons of rock and roll crunch. If your bored with your normal EL84 tone these are definitely tubes to consider. Not recommended for some VOX amps as well as some smaller Mesa Boogie amps due to size issues.

Tesla / JJ EL84 - This tube has been a personal favorite of mine so the review is not entirely unbiased. With the JJ you seem to get a compromise between tone and reliability. Nice mids, sparkling highs and solid bottom end characterize this tube. From a construction standpoint I think JJ has hit the mark. As with any EL84 they can be prone to mechanical noise in combo amps. However, they seem to take the heat and vibration in stride without any negative tonal effects. In the AC30 the JJ tubes really delivered the VOX chime with lots of swirl and shimmery harmonic content. In the little Pro Junior just crank it up and you get a great, nasty, overdriven sound. That’s not bad, it’s good. When pushed hard into the land of the square wave they remind me a lot of a good 6V6. If you have tried the OEM Sovtek’s that shipped in your amp it’s worth your time to try a set of JJ EL84’s. Many convert and never go back. In cathode biased amps you can generally plug and play for that hot creamy “woman tone” that so many desire.

http://thetubestore.com/el84review.html

Rz

8 de junio de 2008

Preamp tube characteristics

Tube mA TC Mu (gain)
12AX7 ECC83 7025 1.2 1600 100
12AT7 ECC81 10.0 5500 60.5
12AY7 3.0 1750 44
12AU7 ECC82 10.6 2200 17-20

mA is current in milliamps. This is standard 1957 industry spec at standard test reference voltage and bias settings.

características de los tubos o válvulas del los pre-amplificadores.

31 de mayo de 2008

cambio de válvulas en mi Tube Driver ... experimentando

me anime, y le probé válvulas diferentes a mi BK Butler Tube Driver (TD).

- ¿cómo abrir la caja ... tiene 4 tornillos en la base (wha-wha) y dos tornillos en el frente.






le escribí a BK y me dijo: los tornillos de las bases. cuidado que el tubo va "pegado" para evitar que se salga durante el viaje de despacho.





- así fue, pegado con un pegamento ... lo abrí con un corta-cartón. corte en torno de la base del soquete que contiene el tubo.




probé
:
JJ ECC803S: un 12AX7 Large Plate.
sonaba bien, pero el drive estaba al 100%. me deja poco headroom ... ¿qué pasaba si me faltaba drive para tocar, por ejemplo, two minutes to midnight? la Eq. equilibrada diría yo.

luego probé el otro que tengo un 12AT7.....

The JJ ECC81 / 12AT7 tube is a low noise and low microphonic preamp tube. A good choice for phase inverters and reverb circuits calling for 12AT7 tubes.The ECC81 tube type is equivalent to the North American 12AT7 tube and can be used in any 12AT7 or ECC81 circuit.

con el 12AT7 bajó el ruido de mi circuito. el drive esta muy bien a las 12:00, es el que uso de overdrive.
quizás un sonido un poco abombado. se supone que debería probar el 12AU7 ...

veremos, habrá que mirar tubos NOS.

21 de mayo de 2008

Aprendiendo de tubos II

UPDATE ... http://kcanostubes.com/content/Default.asp
nuevo sitio para revisar


se supone que el tubo "hace" la diferencia.

revisen este link, tiene muy buenas explicaciones de tipos de tubos diferentes.
http://store.tubedepot.com/index.html

sin embargo yo fui directo a: http://store.tubedepot.com/no.html la sección de tubos N.O.S. (New Old Stock).
son tubos antiguos de verdad. la oferta es escasa y algunos tubos son bastante caros ...

a mi me llamaron la atención los siguientes:
http://store.tubedepot.com/nos-12ax7-telesp.html
http://store.tubedepot.com/nos-12ax7-mullard.html
http://store.tubedepot.com/nos-5814asiemens.html
http://store.tubedepot.com/nos-12au7-mullard.html
http://store.tubedepot.com/nos-12au7-rca-bp.html

voy a tratar de comprar algunos de estos para probarlos en el Butler Tube Driver y en que me hizo DSM Noisemaker.

RedZ On Line